Friday, November 19, 2010

Large Dogs and Small Trees

Photo0145I have a large dog and a smaller auxiliary dog. Here is a photo of the former and, yes, he is sleeping on a twin size foam mattress. This is one of the reasons I garden in raised beds. Seriously, the beds are not raised high enough to keep either dog out; the Lab can jump four feet from a standstill. However, they are very good boys and just having the beds two feet higher than the surrounding area reminds them-most of the time-it is a no-go zone. Fortunately, the Dane is too dignified to jump and doesn’t like to get his feet muddy, so my beds are safe, at least from his oversized paws.

C. j. TensanI can’t explain why someone with an affinity for preposterously large pets would have a passion for tiny trees. It’s peculiar. If you are charmed by the smallest of conifers, like I am, their best use is a space devoted primarily to them-such as an alpine bed or trough. These tiny tykes, labeled “miniatures”, tend to get lost in the mayhem of a vigorous perennial border. Even in a small bed or even a container on a balcony you can suggest a woodsy ambiance using wee conifers. This is the classic use of those hypertufa troughs you see in garden magazines.

In any vignette that is preponderantly coniferous you can ensure interest by grouping a variety of shapes. Obviously, a spreader, a globe and a cone will be far more interesting than 3 balls. Maintain scale by using the same size category in your grouping. By combining your collection with well-behaved alpines and smallerIMG_1060 perennials, you can create a bed that is beautiful and always interesting. Another plus; I might point out that conifers are the original low maintenance plant. No pruning, deadheading, staking, raking, or feeding required.

I’ve created a modified rock garden in my yard that has a variety of sizes and types of plants. It’s a work in progress as I remove what doesn’t work to make room for what does. I have used mostly dwarf conifers, but also some miniatures and a few intermediates. One key to utilizing the different sizes is to arrange them in decreasing size, from the back of the bed to the pathways or to the front of the bed. It creates a trick of perspective, reducing the difference in size through distance. In an even grander setting, you can use large garden conifers to serve as a visual bridge between towering trees beyond your garden and your smaller cultivated plants. This is an example of the design principle called sequencing.

Dwarf and intermediate conifers can be used effectively in garden borders. Remember that conifers are like teenagers; they need their space. Neighboring foliage that overlays the branches of the conifer can cause serP. o. Skylandsious damage. If you lose branches, it will never fill in; only a very few conifers such as Thuja and yew will break from old wood. Evergreens serve as anchors in the seasonal displays of the garden and provide year round structure and interest. Upright conifers of intermediate size such as the columnar Chamaecyparis lawsoniana ‘Ellwoodii’, the pyramidal Picea orientalis ‘Skylands’ or the graceful Chamaecyparis obtusa ‘Gracilis’ make outstanding vertical accents in the border.

Dwarf conifers also contribute significant color interest in the garden. Not only do they come in every shade of green from the pale spring green of new growth on firs to the deepest dark green found in the yews, but also silver, yellow, blue, purple and orange. Not to mention variegations of white, cream and yellow. Some conifers sport new growth that contrasts with the old growth creating an interesting scheme. Some bear colorful cones, notably Abies koreana ‘Silberlocke’ and Pinus pumila ‘Dwarf Blue’ (yowza!). A few conifers contribute colorful fall foliage, such as Larix kaempferi ‘Nana’.

Others, intriguingly, change color in Photo1040the winter and then return to their accustomed summer hue-without dropping their needles. Some Cryptomeria japonica that are green in summer turn almost purple in the winter. Thuja occidentalis ‘Gold Drop’ is yellow in summer and picks up orange tints in winter. Podocarpus ‘County Park Fire’ changes color from season to season, somewhat randomly and indescribably. Right now mine is sort of puce, which is a rather unfortunate sounding but interesting hue.

You can see why I’m cuckoo for conifers. Hopefully, if you were suffering from the mistaken impression that conifers were all large green amorphous cones, I’ve given you a whole new perspective on plants with naked seeds.

Tuesday, November 16, 2010

Mysterious Miniatures

J. c. Compressa

Several years ago I was working with a client who wanted a rock garden. The study and research I did in preparing to design that project kindled in me a love for dwarf conifers. Ultimately, I took the most prominent raised bed in my yard and re-imagined it as an alpine garden. That bed currently showcases 29 different dwarf conifers and I’m starting to cast my eye on two more beds that have suitable conditions.

Dwarf conifers are mysterious. There are only a few that come to us from the wild: Pinus mugo is from the Alps, Pinus pumila from the mountains of Japan and Juniperus horizontalis is native to the Eastern US. Many times, what appears to be a dwarf form in the rocky, inhospitable wild becomes a towering giant when transplanted to a well-tended garden.

C. j. YokohamaSo, what is the source of dwarf conifers? Some are selected from the seed flats of commercial growers. There can be considerable variety of color, form and growth rate when many thousands of seeds are sown. More often, dwarf and miniature forms are shoots that are taken from tight balls of slow growing ‘witches broom’ found on normal size trees. Witches brooms seem to be a result of injury or pathogen. These shoots are grafted onto cultivated root stock and frequently retain their uniqueness. They may even produce diminutive cones with seeds that reliably produce dwarf offspring.

There can be a lot of confusion when it comes to designating conifers as “dwarf”. Sequoia sempervirens ‘Adpressa’ is a choice dwarf of the coastal redwood. People are shocked when it tops out at about 75 feet tall, but  the species gets 300 feet tall. At its broadest, the definition of a dwarf conifer is “one that fails to attain the size and stature of the parent plant.” For my purposes, it has to stay a lot smaller than that! The American Conifer Society is recommending that these be called “garden conifers” as opposed to “dwarf conifers” in an effort to alleviate some of the confusion. In addition, the ACS has adopted the following four size categories for conifers:

Category

Growth per year

Size at 10-15 years

Miniature

less than 1 inch

1 foot or less

Dwarf

1-6 inches

1-6 feet

Intermediate

6-12 inches

6-15 feet

Large

more than 12 inches

more than 15 feet

C. l. EllwoodiiUse caution when selecting your dwarf conifer. Names can be very perplexing and tend to be confused in the trade. For example, there is a group of Chamaecyparis lawsoniana labeled ‘Elwoodii.’ C. l. ‘Elwood’, a lovely blue pillar, may reach 15’ tall and 5’ wide. C. l. ‘Ellwood’s Pillar’ looks identical in the pot but matures at 4’ tall and 15” wide. There is also ‘Ellwood’s Pygmy’ (2’ tall), ‘Ellwood’s Nymph’ (12 feet tall) and several others. Ellwood was a busy guy.

P. a. Little GemMake sure the plant you want to purchase is indeed slow-growing. It should have short internodes, which will show that it is growing at the Miniature-Dwarf rate. An open, loose structure indicates a faster growth rate. Slower growing plants tend to be expensive but not as expensive as buying a plant that quickly outgrows its space and must be replaced.

In addition to categorizing the size of conifers, the ACS also defines shapes. Many people expect a conifer to be conical, like a classic Christmas tree. Conifers, especially dwarf conifers, come in many different shapes with exciting design possibilities:

  • Globose: globe-like or rounded in general outline.
  • Pendulous: upright or mounding with varying degrees of weeping branches.
  • Narrow upright: much taller than broad; includes fastigiate, columnar, pyramidal or conical.
  • Broad upright: includes all other upright plants with do not fit into categories 1-3.
  • Prostrate: ground-hugging, carpeting plants without an inclination to grow upward.
  • Spreading: wider than tall.
  • Irregular: erratic growth pattern.
  • Culturally altered: pruned or trained into formal or imaginative shapes, such as standards. T. c. Stockman's Dwarf

Texture varies widely between and even within species. Hemlocks have short needles, Pines are quite long. Fir needles are stiff. Some Chamaecyparis have soft, touchable feathery foliage, others have stiff fans. Some conifers are loose and open, others tight, congested and dense.

Dwarf conifers provide continuity through the seasons and contribute an incredible variety of form, size, color and texture to the garden-even in the snow. Flowering plants will come and go but conifers will endlessly delight you.

Wednesday, November 10, 2010

Coniferous Splendiferous

I live in the Evergreen State. Our state tree is the Western Hemlock. We have over 30 native conifers including varieties of Juniper, Cypress, Cedar, Fir, Spruce, Yew, Hemlock, Redwood, Pine, and Larch. There is little wonder that I am fascinated with these sturdy and beautiful botanical stalwarts.

There are a lot of misconceptions about conifers. Did you know that not all conifers are needled nor do all of them bear classic, brittle, scaled cones? However, one thing is true of all coPhoto1028nifers: they belong to a class of plants that bear naked seeds as opposed to the rest of seed bearing plants whose seeds are enclosed in ovaries. The class is Gymnospermae and contains three botanical orders: Coniferales which typically bear classic cones; Taxales, which includes the yews, bear less recognizable “cones”; and Ginkgoales which, obviously, is the classification for Gingkos -the only broadleaf plant in the class Gymnospermae.

Conifers may be single trunked or multi-trunked. Most, but not all, conifers are evergreen. Larix (larch) are the most common deciduous conifers and, like Ginkgos, typically have colorful foliage in the fall. The immature cones are the “flowers” of the conifer. Most bear both male and female cones but a few, like yews and junipers, are dioecious. Yews and junipers are also different in that they carry their seed in structure that is botanically similar to what we would recognize as a cone, yet more resembles a fruit.

The female cones have two types of scales; the outer is sterile and protective, the inner scales hold the seed. It can take up to three years for the seed to mature. Some conifers require heat, such as a forest fire, in order to disperse their seed. The ripe cones may be carried for 20 years before fire releases the seed to drop onto a bed conveniently cleared of competitive plants.glaucous

In the wild, conifers often live in poor, dry soil and sometimes summer drought, though firs and hemlocks tend to prefer cooler climes and consistent moisture. For an especially low water use area, choose pines or a conifer with glaucous foliage. The blue shade results from a waxy coating that inhibits moisture loss. Generally, conifers for the garden want to be planted in well-draining soil that is amended with some organic material. Avoid low spots and don’t position soaker hoses directly over roots. Most conifers are petulant about wet feet and will drop needles and look scruffy in that environment. Taxodium are an exception; commonly referred to as swamp or pond cypresses,they can be found growing natively in standing water. To a lesser extent, Larix and Thuja are somewhat tolerant of poorly drained soils.

The best time to plant conifers is: not summer. Planting them in autumn through early spring will give them a chance to adapt before the summer stresses hit. Make sure to untangle any circling roots and that you do not plant it too deeply. Even if your new conifer will be drought tolerant, it will need consistent water during the first summer.

C. d. KnaptonensisAlthough conifers generally prefer full sun, some of the variegated versions, especially the Cryptomeria, appreciate some shade. Also, Taxus and Chamaecyparis will tolerate some shade. Conifers need their space and will sulk if crowded. Branches will drop needles or even die if overlaid with neighboring foliage. Some needle drop is normal although most conifers don’t replace their needles each year like deciduous trees. Needles may last from 1-3 years, but eventually they drop; this is sometimes called “flagging.” As long as the new growth is strong, lost needles from old growth should not be concerning.A. l. Arizona Compacta

Conifers tend to be quite sturdy if not stressed. Notable stressors include poor drainage, air pollution, damage to roots or to bark and soil compaction. Give your conifers a suitable situation and they will give you year round, season spanning structure and beauty. It’s an excellent exchange.

Tuesday, September 21, 2010

End of a Bloomin’ Cold Summer

Photo0887 Normally, I love autumn. I love the changing colors, the nip in the air, having a fire at night. I love sweaters and boots, the smells of pumpkin bread and of newly sharpened pencils. I even love the early nightfall that provides more time for catching up on all that reading that has been stacking up over the summer. But, seriously? Summer was way too short and far too cool this year. As usual, it didn’t begin until after July 4. Usually, it continues almost into October, but this year, summer gave out around the last week of August. Even our local news commented:

…conditions cooler than normal for most of the summer. Seattle's April-to-August average temperature through Aug. 27 was 58.9 degrees…

However, despite my reluctance to let summer go, there is a lot going on in the garden this fall. I am still enjoying'Madame Emile Mouliere' a good variety of blooms. Some of my favorites this year are the hydrangeas. They are  blooming like crazy, providing armloads of cut flowers and still making a great show. The Hibiscus syriacus are also lovely; ‘Blue Bird’ just finished its parade of shining, single blue flowers and ‘Blushing Bride’ is still going strong with smaller but fully double pale pink blooms. Clethra alnifolia has fragrant white bottlebrush flowers that will soon give way to golden fall foliage. The bees are besotted with the Caryopteris; ‘Jason’ has bright yellow foliage with blue flowers; ‘First Choice’ has green foliage but a dense habit and dark blue blooms.

Nigra Magnolia liliflora ‘Nigra’ puts on its main event in spring when the large, dark pink blooms show dramatically against the nearly bare branches. I always get a few blossoms popping out all summer and through the fall, but this year the tree is covered with blooms, as if it is hurrying to get them all displayed before frost. Many of the roses are in full bloom once again, notably Rosa ‘Golden Celebration’, ‘Just Joey’ and ‘Graham Thomas.

Some of the perennials have been blooming for months. Astilbe chinensis pumila, for example; also CoreopHeliopsis 'Loraine Sunshine'sis verticillata, Heliopsis ‘Loraine Sunshine’, Potentilla nepalensis ‘Miss Willmot’ , Knautia macedonica and Veronica ‘Giles van Hees.’ Geranium sanguineum ‘Max von Frei’ and ‘Lancastriense’ and Campanula ‘Birch Hybrid’ have been in bloom since early May.

Actaea simplex 'Brunette'Other perennials have been waiting till now to put on their show.  Aster fritarkii and A. ‘Purple Dome’ love the sun, but A. divaricatus will bloom in some shade. Actaea simplex ‘Brunette’ has wonderfully fragrant white bottlebrush blooms against dark brown foliage. Other perennials famous for fall bloom are in full flower, such as Crocosmia, Dahlia, Fuchsia, Helenium, Rudbeckia, Sedum and Solidago.

Lobelia is a great plant that blooms in autumn. Most people are familiar with annual lobelia, a bedding plant with brilliant blue flowers held close to a mat of green foliage. I’m speaking of perennial lobelia. L. syphilitia is a rangy, somewhat coarse plant with great spikes of blue blossoms. L. cardinalis is slightly more refined with scarlet red blooms. Hybrids have beeLobelia 'Monet Moment'n selected with both refinement and beautiful colors. Lobelia ‘Monet Moment’ has exquisite  magenta spires on slender stalks; L. vedrariensis is a looser in form with purple flowers; L. ‘Grape Knee Hi’ is, predictably, a more compact purple version. All of the lobelias provide a great form contrast to the daisy type flowers that predominate in fall.

All in all, that is a lot of consolation for the early departure of summer.

Saturday, September 18, 2010

Happy Fall, Y’all

You may have noticed some gardeners have strong opinions about fall maintenance. The two camps are represented by those who believe the garden needs a good scrubbing, so to speak, before being put to bed; and those who believe nature has been my dogtaking care of itself for a long time and needs little assistance. I don’t really have a dog in this fight (as you can see, my dog is a lover, not a fighter), but I can offer suggestions that seem sensible.

First of all, if you have worked to create a garden full of lovely autumn vignettes, you don’t want the detritus of fall to detract from their beauty. Just as in high summer, you will want to continue to remove anything tatty from the composition. Weeds will stage a coup and take control of your garden over Seattle’s mild winter if not fended off. Weeding, deadheading and Echinacea and Origanum removal of spent foliage goes on. Remember that anything diseased should be destroyed. If you leave it in the garden, you will surely see it again next year. Everything else can go into the compost for next year’s mulch.

After the first hard frost, remove the leaves from the beds. Leaves left in the beds over winter and harbor insect pests, bacteria and fungi. Even large perennial leaves, like those of hosta, should also be removed to eliminate a favorite slug habitat. I use iron phosphate bait which I try to put out twice a year, in April and October. Large leaves, such as vine maple, can smother lawns and even small plants. If you are able to effectively shred your fallen leaves with a mower, you can leave them right where they are and their nutrients will benefit your lawn. I’ve never been able to do this, perhaps because it is so wet this time of year.

After frost, you will also cut back your perennials, but be judicious. Some of the seed heads, pods or sturdy stalks are architecturally interesting and can attract birds to your garden to entertain you and provide some late season pest control. OrnamDeschampsia and F. 'Tom Thumb'ental grasses provide interest and movement in the winter garden and, in any event, they are petulant if you cut them back before spring. Like some perennials, notably mums and fuchsias, they will overwinter more successfully if you leave at least 10” or so of this year’s growth. Snow will potentially collect around the crown and insulate the plant during the coldest days. Just last year’s stems alone appear to give these plants the bit of cover they need to return for another year.

Fall is when you divide spring blooming perennials and plant new ones, as well as spring blooming bulbs and transplanted trees, shrubs and perennials. Some passionate dahlia aficionados will dig and store their bulbs; I have tried this and never been successful. I was treating my dahlias as annuals until I got a tip from Cisco. Now, when  I cut my frost blackened dahlias to the ground, I cover them with fern fronds and then evergreen boughs. It seems that most of the problem with dahlias, fall pinkswhich are native to Mexico, is not the cold in our Zone 8-9 gardens, but the RAIN! Keep them mostly dry (some rain filters through both the fronds and the boughs) and some varieties will return for you year after year. Try this with any bulb that detests wet feet.

Many gardeners, especially in very cold areas, mulch in the fall to regulate the soil temperature and protect roots from frost-heave. I mulch in late winter for weed suppression and moisture retention. Remember that if you decide to use bark, you must add nitrogen to compensate. The decomposition of the bark uses all the available nitrogen in the soil. If you use compost, you are improving your soil every time you mulch.

Basically, my approach to fall maintenance is: if I like it, make it look good. If I don’t like it, rip it out. If a little work in the fall can eliminate a lot of work later, do it. Actually, that is my approach to a lot of things. Try it-you may like it.

Tuesday, September 14, 2010

Can You Dig it?

Those of us who live in the Seattle area can tell when fall arrives. The date depends not only on the vagaries of our climate cycles, such as El Nino but also on the given property’s microclimates and proximity to the Sound or to the mountains. Even though it may still be sunny there is a distinct nip in the air, usually sometime in September. It foretells months of shortened days and the rain, wind, and snow ahead. It is easy to be discouraged and want to batten down the hatches till spring. However, autumn is a season full of promise in the ghelictotrychonarden.

Fall is the ideal time to plant all kinds of things from ornamental grasses and perennials to evergreen and deciduous trees and shrubs. Of course, plants of borderline hardiness should not be planted in autumn. Fall begins about 6 weeks before the first hard frost-that averages mid-November in Seattle. So, our window for fall planting is during September and October.

Why is fall planting so good for plants? Cool, misty days are perfect for planting any time of year as they reduce transplant shock. The return of the rain is particularly auspicious for planting evergreens, trees and shrubs which may fail to thrive when planted in summer heat and drought. However, in the PNW, all hardy plants benefit from planting in the fall. It is a rare autumn indeed where we would need to give supplemental water in Seattle once the rain starts.

In addition, the warm soil of fall encourages root growth. It’s  estimated that 80% of root growth occurs in the latePhoto0091 summer and fall. Roots continue to grow through the winter until the ground freezes. In early spring, roots continue to develop before top growth begins. While the fall-planted specimens are already becoming well established, the same size and variety planted in spring gets a slow start due to cool soils and lags behind in development. When summer finally arrives, the plant installed in autumn is far better equipped to deal with our dry Mediterranean summer, largely due to its well established root system.

There are other good reasons to plant in the fall. The cooler weather tends to reduce pest and disease problems. Also, it is an excellent idea to buy plants in their season of highest interest. QTupelouality and intensity of fall color may vary even within a particular variety, so when you buy during the season you can ensure that you get the color you want. Many plants are on sale at nurseries. Selection is reduced but sometimes the discounts reach 60-70% off the original price. Autumn is the perfect time to assess your garden. Decide what worked well this year and what didn’t. Does your garden give you beauty to look at in the fall? Just a few plants with gaudy autumn finery can make it spectacular. 

Now is the perfect time to improve your fall garden. Next year you will be glad you did!

Sunday, September 12, 2010

Analyzing Autumn

Have you been admiring local fall landscapes that are starting to flaunt their foliage? “Fine Gardening” has a terrific layout and some great articles in the current issue.1 title page Gorgeous gardens in the fall don’t just happen. I have some suggestions that will help you create an autumn garden that gives you great pleasure.

First, take some time to analyze your garden as it is. Walk through your property this fall-more than once-and make note of what is interesting and admirable in autumn. Take notes or photographs; what is it that you like? What is missing? Think about where you are when you are most likely to observe the garden during the fall months. There will be windows through which you look; the sidewalk, the driveway, front and back doors. Where else?

How much time, money and space do you want to devote to the off-season interest in your garden? How about strategically placed containers? (Don’t forget that plants overwintered in a container should be rated 2 zones hardier to insure viability.) It’s been said that if you limit your efforts to your front walk, it is probably all that is necessary for the majority of your visitors. But, think also of yourself and your family and where you might enjoy some color or fragrance in the autumn.

Consider rearranging plants you already have from singleton positions to create lovely autumn vignettes. Make sure that the cultural cond25 shishigashiraitions for all of the plants in a group is the same. One of the challenges and also the greatest satisfaction in gardening may be in creating pleasing plant combinations which together have a greater impact than the individual plants. Create color echoes between berries and blooms, foliage and grasses. If you have a tree with stunning fall color, pick some leaves and carry them with you to help select companion plants that will pick up the same tones.

Make a note of any microclimates that might influence where you site plants for the fall; a sun facing wall will store a bit of solar heat; the bottom of a slope is a frost pocket, protection from winter winds will improve the odds for a marginally hardy plant.

Keep a running list of plants that you would like to include in your garden. Visit nurseries, public and private gardens during the fall. You can check out what the plants actually look like and how large they become. This is really important; one of our local garden writers talks about the cute, puppy-like quality of plants at the nursery. They beg you to take them home and slip them into the garden somewhere and then they become the Hound of the Baskervilles.

Take photos-to remember what you like and also to get assistance in identifying plants you don’t recognize. If possible, revisit your favorites in winter, spring and summer, because if you 15 aster fritarkiiacquire a plant, you will have to look at it through all the  seasons. Some nurseries, such as Wells Medina, have exquisite seasonal containers full of shrubs and perennials-a great place to get  ideas for stunning plant combos. Read everything you can find on plants that shine in autumn. The local library is a goldmine of information. I keep a list of garden books that I see recommended or reviewed, then I use the winter months to catch up on all that reading.

Keep a notebook of photos, magazine pages, and internet printouts of plants and ideas that appeal to you. You can keep your notebook electronically using OneNote or EverNote. The internet has an astounding array of horticultural resources. Take your time and do your research. But after all is considered, don’t be bullied into choosing some ballyhooed brute with one season of interest that is too big, too coarse or too temperamental for your garden. Choose the plants that are best for you. Then integrate your carefully chosen trees, shrubs and perennials into a design with all year interest.

Saturday, August 21, 2010

Not Your Average Bearded Lady

Bearded irises are sorted by size into several categories. Miniature dwarf reach a height of 8” or less and their blooms are around 1-2” in diameter. Standard dwarf get 8-15”, intermediate reach 16-27”; miniature tall (excuse me?) grow to 16-25” and produce small flowers; border iris are 16-27”. The grandes dames are tall iris (is that tall? Or tall tall? Big tall?) that can reach 38”. Bearded iris tends to bloom by size in order from smallest to largest.

So, as a miniature dwarf, Iris pumila is one of the earliest blooming of the rhizomatous irises. Though not nearly so early as the tiny reticulated irises, I. pumila shows promising buds before the end of March and can be in full flower in April.

Iris pumila is a natural hybrid between Iris pseudopumila and Iris attica that is native to central Europe. Its native habitat is dry grassy lands; like other bearded iris it loves to bake in the sun and hates wet feet.  A raised bed or rock garden will insure perfect drainage. Place this tiny titan at the front and give it room. Division is usually required in the third or fourth year; you will want to do it as soon as the blooms have faded. If you must fertilize be sure to use low nitrogen and be stingy.

Iris pallida, sometimes called sweet iris, orris or Dalmatian iris, is native to the Dalmatian coast of Croatia.  This rhizomatous bearded iris produces fragrant, pale lavender-blue flowers with yellow beards. In late spring to early summer, blooms appear atop stems which may get to 40” tall. I always thought that ‘Variegata’ had cream and green variegation and ‘Aureovariegata’ was green with yellow stripes. According to the Missouri Botanical Garden, these two varieties are synonymous and feature gray-green leaves variegated with stripes of creamy yellow. Despite its association with the tricky bearded iris clan, it has been selected as a GPP for the Pacific NW.

To make things more confusing, Iris pallida ‘Argentea Variegata’ (aka ‘Albo viris pallidaariegata’) does have pure white variegation attributed to its leaves. However, the GPP organization characterizes this variety as less vigorous than ‘Variegata’. Whatever variety you choose, this is one iris whose foliage is more beautiful than its bloom-and since the bloom is both pretty and fragrant, it is a no-lose proposition.

Iris unguicularis (née Iris stylosa) is the winter blooming Algerian iris. It often starts in October and produces blooms through March or even April and is considered hardy in zones 7 to 9. When the temperature dips below about 10 degrees, however, any flowers and buds will freeze and be lost. Happily, if the weather warms up, the plant will re-bud and be in full bloom again within a week.

Iris unguicularis has tough, sometimes ribbed, leaves ½” or less in width and anywhere from 1-2 feet long.  The plant can be unprepossessing, but the flowers are dramatic-especially in the dead of winter. Blooms tend toward shades of lavender but can be pure white to deep purple to slightly reddish. The flowers are sweetly scented and can be cut and brought inside.

This iris is native to the dry Mediterranean climate. It is a bit tender and if the temperature drops to 0° F. the foliage will die to the ground. Usually it will recover and in the spring grow new foliage. I. unguicularis can survive the winter cold and even the steady rain of the PNW, but it requires excellent drainage and a good baking in the hot summer sun. If you plant it against your foundation on the south side it will enjoy the heat, stay dry in the summer and the lime leaching from the concrete will contribute to the neutral to slightly alkaline soil it prefers. At the least try to find a south facing section of your garden in the full sun.

It resents drying out completely; you may need to water once or twice during the summer if there is no rain. The flowers are held low in the evergreen foliage and you might want to cut it back to about 10” in late August so that you can enjoy the flowers. Like most irises, a low nitrogen fertilizer can be applied before and then after flowering. The biggest problem you face with this unique iris is slugs. Imagine their delight upon finding this treat in midwinter. You must be diligent about baiting for slugs or you may never see any flowers.

Iris unguicularis may be propagated by dividing the rhizomes, but I have found in my garden this plant is slow to colonize. You can also allow the seed pods to dry on the plant and collect the seeds or allow the plant to self-seed and then move the seedlings. It may take two or three years for the plant to produce flowers.

What an amazing genus. You can have some kind of iris blooming almost any month of the year if you are willing to hunt for them!

Tuesday, August 17, 2010

Recalcitrant Rhizomes

The time has come to face the music and talk about the difficult but delectable rhizomatous irises. Iris germanica is the most familiar and probably what you remember seeing growing with wild abandon in hot sunny climates. Almost all bearded iris hybrids descend from wild forms of Iris pallida (Sweet Iris) and I. variegata (Hungarian Iris).

The model for the fleur de lis, blossoms of this stately beauty are instantly recognized. Three upright petals are called “standards”, and three pendulous petals are called “falls”. The falls are adorned June 005with bristly hairs that earn this lovely lady the moniker “bearded.”  Bloom stems carry multiple buds that flower in succession and make them desirable for the vase. Many of them are wonderfully fragrant. "Remontant" Iris, or "Reblooming" Iris  have a genetic tendency to bloom a second time in late summer or fall.

Bearded Iris have a reputation for being sturdy, long lived and low maintenance. Why do they turn into such prima donnas in the PNW? They don’t like clouds and they don’t like wet feet. Bearded iris will endure droughts with finesse, but they cannot tolerate soggy soil. They require baking in the hot, full sun with their rhizomes exposed like sunbathers on the beach at Nice. (Some people should not go topless. I’m just sayin.)

Still, they can be grown successfully here. Make sure the spot you choose has full sun and good drainage. As much as 50% of the rhizome should be above ground; planted too deeply they produce leaves but no blooms and are more susceptible pink iris to soft rot and iris borer. Do not mulch them or they will sulk. Planting on a slope or in raised beds improves drainage. It may help to dig your hole, form a mound at the bottom, and lay the rhizome with the roots splayed down the sides. Firm the soil around the rhizome and then water to help settle the soil. Once established, Iris don't require watering. Overwatering is strictly verboten.

Irises thrive in almost any type of soil provided it is well-drained. You may fertilize in the early spring, if you like. Iris enjoy bone meal, superphosphate or any good 6-10-10 fertilizer. Be sure to avoid using anything high in nitrogen, as nitrogen encourages rot problems.

If, despite your best efforts, your iris leaves look tatty after bloom, remove them immediately. In the late fall or early winter, cut healthy leaves back to about six inches. Avoid using mulches, ground covers, or anything that covers your rhizomes or they will rot. Excessive moisture and rainy or humid weather can lead to yellow and brown leaf spots. Always remove old dead leaves, and cut off and destroy any leaf or part of a leaf that is affected.

When your iris clumps become crowded, the bloom will taper off and they must be divided. Dividing every 3-4 years should prevent a season without bloom. The best time to divide your013 iris is August. Save divisions from the perimeter of the clump and cut the leaves back to one third when replanting. You can dig the clump or, if you are confident in your excision skills, you may remove the centers of the clumps with your spade and leave the newer growth undisturbed. Remember that about 25% of Iris won’t bloom the  first year after planting. Sometimes they need an extra year to become established.

Give your German Iris plenty of sun, great drainage and room to bloom and they will make you proud. A little Wagner played full blast in early summer with the windows open won’t hurt.

Monday, August 9, 2010

An Iris by any other name is still an Iris

I’d like to introduce you to some of the more eccentric members of the iris clan. These iris are all well suited to our misty, moisty PNW; several are even considered pond or bog plants. With a little fortitude, you should be able to hunt them down. Don’t forget plant sales, they are an excellent source of the more unusual flora. The Snohomish County Master Gardener Plant sale is usually the Saturday the weekend before Mother’s Day in May.

Iris setosa var. arctica is one of my favorites. This tiny but lovely iris has grassy leaves and lavender to purple blooms with arresting silver veining. It’s ideal home is a situation where it won’t be crowded by larger plants, in full sun with moist soil. However, it is easy going and sturdy and will tolerate almost any soil, part shade and average moisture. This plant is native to Alaska, British Columbia and Siberia.

Iris ensata (Japanese Iris) can  live in partial shade but prefers bright, sunny locations. Ideally, they thrive in moisture-retentive, acidic soils with plenty of humus but they will grow well in any decent soil if they receive enough water. They require high soil moisture and can even be grown in  containers in pond ledges. They are grown this way to great Iris ensata at Oregon Gardeneffect at the Oregon Garden. Apparently, in winter they are narrow-minded about standing water or even boggy soils where rhizomes may rot. Plants may be grown in pots sunk half way in water during the growing season and then removed for fall and winter.

Iris foetidissima (Gladwyn iris) is well suited to the PNW. It is usually grown for its striking orange fleshy seeds in late autumn and early winter and not for its relatively insipid blue flowers. There is a variegated variety listed as a Great Plant Pick that is grown for its lovely evergreen white striped foliage because it rarely flowers and therefore, rarely sets seed.

Iris chrysographes is the bewitching black iris. Some call it a Siberian iris but, although it is similar in appearance, it hails from China, not Siberia. It grows in full sun to part shade and, like the Japanese iris, enjoys moisture and can even be grown pond-side.

Iris cristata (dwarf crested iris) is native to the United States typically appearing on rocky, wooded slopes and along streams. It prefers organically rich, moist but well-drained soils in full sun to part shade. It will tolerate almost full shade but if grown in full sun, the soil must be kept consistently moist. This is a vigorous spreader that grows 3-6” tall with nearly stemless flowers. If well pleased, it forms dense colonies that produce a spectacular drift of blue in the spring.

The Louisiana iris originates, as you might expect, from the gulf states of the US bLA Iris From SLI websiteut they are hardy to USDA zone 5. Natural hybridization occurred within five wild species originally found in the bayous of the Louisiana basin resulting in an astounding variety of colors and shapes. Not only hues of purple, blue, yellow and white are represented but also copper, peach, pink and almost red. Some have thin petals, some have upright standards, others are extremely wide and flat. I am on full hunt for this beautiful creature! Learn more about the history and origin of this fascinating plant at the Society for Louisiana Irises.

They will grow in full to part sun and the wetter the soil, the more vigorous the growth. They may be grown in average garden soils but prefer moist soils or submerged in a pond. They are relatively heavy feeders and will enjoy a balanced fertilizer in fall and again in late winter. After blooming in spring, the plant will go dormant and you may trim the foliage back to 2-3” above the ground.

Iris tectorum (Japanese roof iris) comes in shades of lavender and there is also a white form. It has fans of wide, ribbed leaves with a thin texture. It grows in full to part sun, but prefers woodland conditions with humusy soil and moisture. It appreciates compost in the fall and a light, balanced fertilizer in the spring, but is a sturdy and adaptable plant.

Truly, these intriguing plants are worth searching for!

Saturday, August 7, 2010

Luck of the Iris

Never one to seek controversy, I nevertheless must admit that I admire the genus Iris. Among the 250-300 species, there are a wide variety of types to choose from and all, in my opinion, are beautiful. Most are fragrant and many are long lived. They divide easily and come in an astonishing array of colors and seasons of bloom. The name Iris first belonged to the Greek goddess who was the personification of the rainbow and was bestowed on the genus as a reference, no doubt, to the wide variety of hues to be found there.

Certainly, many irises are a challenge to grow in the cool and cloudy Pacific NW. Some gardeners eschew these lovelies because they require heat, drainage and sun and their foliage has a tendency to become tatty and unkempt. So, I will start with the easy going, mostly non-rhizomatous types that are less intransigent.

Iris r. 'Harmony'Dwarf Irises include winter blooming Iris reticulata, I. danfordiae and  hybrids which I covered in a previous post. These bulbous iris are only 4-6” tall, so you must plant them where they may easily seen in the winter and very early spring. Happily, most of the perennials have yet to emerge when these iris bloom in January and February, so although they are small, their bright colors may be seen at a distance. The grassy leaves may continue to grow to 18” after blooming, so site them where you can hide their ripening foliage.

Dutch Irises grow from bulbs and bloom in mid spring. Both Iris xiphium and Iris x hollandica are commonly called Dutch Iris. (Iris xiphium is also called Spanish Iris; this is why I prefer botanical names!) They have long straight stems and lovely blooms so they are frequently used in floral arrangements. Like most iris, they require excellent drainage and prefer full sun but can be grown in part shade. Like most bulbs, the foliage must be left to ripen on the plant and store food in the bulb for next year’s bloom. Don’t remove the foliage until the leaves are yellow. You may lift the clump at that time and separate the bulbs to propagate.

Siberian Iris tolerates a wide range of conditions, thriving in damp and even wet areas. They are most floriferous in full sun, but also bloom in partial shade. They’re not bothered much by iris borer, bacterial soft rot or other iris problems. Their roots are more fibrous than the fleshy rhizomes of bearded iris.

Iris s. 'Butter and Sugar'Known for their graceful appearance, Siberian irises produce arching  grass-like leaves that stay green all summer. In late spring they produce delicate beardless blooms in shades of maroon, white, pink, blue, purple, and yellow. Siberian iris may need to be divided every three or four years to promote abundant blooms. In early fall, cut back the foliage to about 6 inches and divide the clump into sections, each with 5-6 growth points and adequate roots.

These are some of the easiest to grow, so if you are skeptical of the lovely iris, at least give these a try!

Saturday, June 12, 2010

Dunn Gardens

Seattle is a city bedecked with horticultural jewels. This spring, I was delighted to visit one of them, the historic Dunn Garden. The garden is located in the Broadview neighborhood about 10 miles north of downtown Seattle. When the property was purchased by Arthur Dunn in 1914, the site offered sweeping vistas of Puget Sound and the Olympics, now veiled by mature trees. Arthur Dunn desired a summer country home for his family and he hired the Olmsted Brothers to design a landscape plan.

This renowned family firm is perhaps best known for designing Central Park in New York and the Capitol grounds in Washington DC. In a prodigious display of forward thinking, Seattle hired the Olmsteds to create a comprehensive plan for major parks throughout the city a little more than 50 years after the Denny party landed at Alki. Seattle's Olmsted park system has an extensive multi-site plan linked by boulevards and is recognized by subject matter experts as one of the best preserved and best designed in the U.S.

The Olmsteds' design philosophy was to retain and enhance the  natural beautyPhoto0253 and native vegetation of the site, working with the existing topography and integrating the planned landscape into its larger surroundings. It was characteristic of an Olmsted plan to include wide, curving boulevards and broad lawns, punctuated by stands of native trees and shrubs. The plan for the Dunn country place took advantage of the panoramic views and large stands of second-growth Douglas firs. Arthur Dunn, an avid and knowledgeable gardener, implemented the plan.

In 1947, Edward Dunn, the second child of Arthur and Jeanette Dunn, converted the garage on the property into his residence. He immediately began creating a woodland garden on the 2.5-acre site where the vegetable garden had been; he tended this garden until his death in 1991. The richness and diversity of the plantings include woodland plants such as erythroniums and trilliums, rhododendrons, and specimen flowering trees nestled beneath a canopy of fir and deciduous trees that remain from the original garden.

Ed Dunn left an endowment to preserve and maintain his portion of the estate. The E. B. Dunn Historic Garden Trust, established in 1993, now owns and manages the property. The resident curators, Charles Price and Glenn Withey, manage the garden’s daily operations. The Dunn Garden Trust's Board of Directors and the Garden Conservation Committee, direct the garden's rehabilitation and preservation.

The Olmsted characteristics to be preserved include certain iconic elements such as the curvilinear circulation system of drives and paths, the massing of plants, and the creation of various 'garden rooms', as well as the spatial relationships between the various landscape features. A spatial relationship is basically the adroit positioning of various elements in the landscape so that the result is greater than the sum of its parts. In an Olmsted design, open lawns are embellished with scattered trees and shrubs that choreograph a sequence of spatial relationships and views throughout the landscape. This defining feature is particularly evident in the design of the U.S. Capitol grounds. Photo0260

The Dunn Garden is listed on the  National Register of Historic Places. The National Register recognizes the garden's significance under two of its standard criteria. The property is noted both as an excellent example of Olmsted design, and for its association with Ed Dunn as someone who made important contributions to the field of horticulture. An enthusiastic gardener and prolific garden writer, Edward Dunn was respected as an authority on Pacific Northwest native plants. He was president of the Seattle Arboretum Foundation and guided the development of its Japanese Garden. He also served as president of the American Rhododendron Society. He was a founding member of the Species Rhododendron Society.

The best seasons to visit the Dunn Garden are in the early spring and in the fall. Early spring will feature snowdrops, magnolia, erythronium, hellebores and hepaticas. The show will continue through mid-May, when epimediums, trilliums, podophyllums, and ferns abound. Thanks to Arthur Dunn’s memories of his home in New York State, the garden includes many spectacular eastern hard­woods, some of which provide eye-popping fall color.

The gardens are open to the public on guided tours on Thursdays, Fridays, and Saturdays from April through July and September through October (closed in August). Admission is $10 for adults, $7 for senior citizens and students. Since private residences are still located on the grounds, admittance is by reservation only, and directions to the site are mailed only after reservations have been made. Children under 12 and pets are not admitted and parking is very limited. You can visit the website, www.dunngardens.org for more information, photographs and reservations.

Visit the Dunn Garden to experience living horticultural history!

Monday, June 7, 2010

Container Maintainer

Before we leave the topic of containers (for now) I want to cover a few aspects of maintenance. The most important rule for containers is: don’t let the planted container dry out. The amount of water  needed to prevent that varies dSw hydrang potepending on several factors. Plastic containers and glazed pots retain moisture better than clay, wood or wire baskets. Containers placed in the shade will require less frequent watering than those in the sun. Some plants are moisture lovers, others don’t like “wet feet”. The weather influences moisture in outside containers. The only way to know when your pots need to be watered is to check them daily. You can either feel the soil, or test the containers weight-or both. Experience will equip you to determine your own plants’ needs.

When you water, moisten the entire root area-add water until it is running out of the drainage holes. If the potting mix is allowed to dry out, it is very difficult to re-wet. If this happens you may need to soak the container. You can submerge the pot in a larger container to the soil level. If the pot is too large, try putting a saucer under it or even a plastic bag around the base and up the sides and run the hose into the container until water stands. This is the only time you are allowed to let your containers stand in water! You should not normally have outside containers sitting in anything that would impede natural drainage. When water fills the air spaces between the soil particles, the roots are unable to function normally and the plants may die. If you must use a saucer-perhaps you have a second floor balcony-half fill the saucer with gravel and place the pot on top.

Remember that container plants planted in soilless mix depend on you for nutrients. Your new plants are accustomed to being pampered. Nurseries feed every time they water to keep plants looking their best. You can feed your container plants with a low nitrogen liquid fertilizer-something like a 5-10-10 ratio. Many people use a slow release encapsulated fertilizer, such as Osmacote. This is a great product, but soil temperature must be above 50 degrees for it to work. Here in the cool PNW, you will get fewer months of extended use. Some soilless mixes have slow release fertilizer incorporated. Either way, even if you do use slow release fertilizer, experts recommend using liquid fertilizer every 3-4 weeks.

To keep your container looking its best throughout the seasons, you will occasionally need to groom your plants. This includes dead-heading, which simply means to remove fad11-04-07_1507ed flowers. Some plants will respond with fresh new growth if you cut them back after they bloom. Annuals need to be refreshed in this way at least once during the summer. You may need to prune trees and shrubs  in containers to improve their structure. In the fall, clean up and  remove dead leaves. There is a marvelous book on maintenance called The Well Tended Perennial Garden by Tracy Di Sabato-Aust. It describes in detail what to cut back, when and why.

If you plan to leave your containers in place outside over the winter, choose plants that are hardy two zones colder than where you live, since the roots of plants in containers may experience more extreme cold than those growing in your garden. In our area, near Seattle, most of us are USDA zone 8 based on the average annual minimum temperature range. If you are close to the water it moderates the temperatures and you can push the hardiness zone a bit higher-so know your microclimate. Many Seattle area gardeners enjoy pushing the envelope and they are successful until we have the occasional below zero winter which wipes out their subtropicals.

Sw pinknorgange If you select plants that are marginally hardy in your area, you may be able to overwinter them by placing in an unheated garage or shed in the fall. Check them a couple of times during the winter-water if necessary. After the chance of frost is over, bring the pots outside, clean them up and water thoroughly. I have been able to overwinter jasmine and fuchsias in this way.

Now is a great time to experiment with your containers!

Sunday, June 6, 2010

Pots and Plants

Many people use annuals for all of their pots; annuals do well because they tend to have a long bloom period. But if you use a bigger pot and a variety of plants, you can still achieve steady bloom all season-and then right on through the winter. Not many annuals can do that! No plant is off limits; consider small trees, dwarf conifers, or shrubs with fall color, spring bloom or interesting shapes. Perennials are fantastic and diverse with varying bloom times for every season. Ornamental grasses provide structure and movement. Bulbs make lovely container plants and many are fragrant. Don’t forget edible plants for utility and beauty.

Whatever combination you choose, white potlook for  colors and textures of bloom, leaf, bark and fruit that please you and complement each other. Why not plant purple sage with a dark leaved geranium; or ‘Bright Lights’ Swiss chard with red twig dogwood and red leaved Bergenia; or white kale with blue fescue grass and white pansies? There are so many options, and so many beautiful combinations.

Try to select plants with similar cultural requirements to share a container. Cultural requirements include sun or shade, dry or wet, hardiness zone…But don’t stress; containers are, by nature, temporary. They are a great place to try out plant combinations before installing them in their permanent homes. Try color combinations that are totally unexpected. See how different foliage textures complement each other and create a design that is better than the sum of its parts. See what it actually means when a tag says “part shade.” If something doesn’t work, switch it out. A large part of the fun of containers is constantly improving on your design skills.

One design strategy that is Sw summer pinkparticularly effective in containers is called ‘color echo.’ Choose your plants so that part of one will echo the colors of another. For example, In this photo taken at Swanson’s Nursery, the magenta blooms of the Phygelius perfectly pick up the pink variegation in the leaves of the tri-color Hebe. It is a no fail way to unite your container while making it very diverse and interesting.

Another design principle is to consider the texture of your plants. A limited color scheme allows the textures of the plants to be of primary signiWM winter yellowficance. In this photo taken at Wells Medina Nursery,  there are no blooms at all in this group of pots, but there is considerable interest. The color palette is very limited-but look at the textures! Yucca ‘Color Guard’ has a bold, lance shaped leaf, Lonicera nitida ‘Baggeson’s Gold is tiny and ovate and Osmanthus ‘Goshiki’ is glossy and serrated. Contrast is provided by the dark, smooth, broad leaves of Bergenia. By the way, this photo was taken outside in mid November!

If you enjoy your perennial container enough to keep it for next year, give some thought to overwintering. Herbaceous perennials by definition die to the ground in winter and return the next spring. If you plan to keep the container in view of the house, make sure you have plenty of woody or evergreen specimens to provide interest in the winter. You can also opt to move some of the summer blooming herbaceous plants out of the container and into the garden for next year and refresh the container with plants that bloom in winter or early spring. (How about bulbs?)

A popular and easy recipe for successful container plant combinations has three components: thrillers, fillers and spillers. Every container should have a centerpiece that is big and bold; that is your thriller. Put that in the center if the pot will be seen from all sides. If you are planting a pot that will be up against a wall or a fence, plant your thriller in the back. Surround that with your filler plants; of course, the spillers go next to the rim where they can cascade down when they get big enough.

Place your plants still in their pots into the container to decide how you want to position them. This is a great idea when you are planting in the garden as well. Sometimes I will try a new plant in several locations-for several days-before I install it. I still end up moving plants multiple times which is a great source of amusement for my husband. He cautions me to never buy a plant that doesn’t come with its own little suitcase because he can guarantee that it is not going to stay in one place for long.

Once you have the plants positioned to your satisfaction, take them out of the pots. If you have a plant that is root bound, there will be very little soil and many roots when you take it out of the pot. If that happens, loosen the roots with your fingers and, if necessary, cut the roots in several places to allow them to spread out into the soil. The minimal damage you do will actually encourage the plant to put out new roots deep into the good soil. Once the plants are in place, fill in with your soilless mix and tamp down to set the plants firmly in place. Remember, we want at least 2” from the top of the soil to the rim of the pot so that the water won’t spill over the rim before it has a chance to soak in. when all is in place, water your container well.

My next post will fill you in on how to maintain, now that you’ve contained.

Tuesday, May 25, 2010

Contain Yourself!

About this time of year, you begin to see lots of advertisements and information about container gardening. Most of them focus on pots and baskets full of brightly colored annuals. Some cities, such as Victoria, BC and Edmonds, WA are renowned for baskets hanging off of every lamppost and burgeoning beds on every street corner. There is no doubt that annuals can make a good show and many are long blooming. However, I’d like to dig a little deeper, so to speak, and consider other interesting and imaginative ways to use containers.

Containers are extremely versatile. Even the smallest porch or patio can accommodate a pot filled with lovely plants. A striking container with just one well chosen plant can make an impression at your entry or next to a pathway or as a focal point in the garden. On the other extreme, you can plant several containers with large scale plants and create a living screen for your patio or deck. Uses of container gardens are unlimited. You can grow vegetables, roseIlex crenata 'Golden Gem' bushes or Japanese maples in your pots. On the Microsoft campus in Redmond you can see massive containers, each holding a Japanese maple or a Katsura tree. On my patio, I have pots with a sturdy central tree or  shrub that remains and I change the rest of the plants with the seasons-or when the mood strikes me.

Containers can be plastic, terracotta, wooden or glazed pottery. Some of my favorite containers were designed and displayed by Wells Medina Nursery in standard metal trashcans. I’ve seen flowers  planted in old siwinter silvernks, wheelbarrows and discarded boots. The Mukilteo Community Garden has an old iron bed frame planted with sedums in a quilt inspired pattern. Gardeners say, “If it holds soil, it’s a container.”Just be sure that whatever you pick to display your plants has plenty of holes in the bottom for drainage. You can make holes in hard surfaced containers with an electric drill and an appropriate bit.

I’d like to opine for a few minutes about soil, because soil is crucial in every type of gardening. An old adage states if you have $10 to spend on your garden, spend $9 of it on soil. This seems backwards, but the truth is, even the healthiest, strongest plant will suffer or even die in poor soil. All plants require water and nutrients, and air is necessary for the roots to absorb these properly. So, drainage is crucial; waterlogged soil will drown a plant.

Since containers generally only drain through the holes in the bottom, they require different soil than the average garden variety. Even a good garden soil is too heavy for containers. Good soil for containers is lightweight, drains well yet holds moisture. In other words, we want the particles that make up the soil to retain moisture but we want the mix to drain well and ensure the roots get plenty of air.

Some gardeners use soil to make their own potting mix which is part mineral and part organic. Mineral ingredients could be vermiculite, pumice or perlite-all of which contribute lightness and good drainage. Organic ingredients might be peat or compost; these contribute moisture retention. These are all added to the soil in varying proportions. When you are starting out, it is a good idea to use a commercial soilless mix; it will save you time and eliminate a lot of variables such as soil borne disease and getting the proportions right. These soilless mixes are frequently called potting soil which creates some confusion. Some are specific to the type of plant, such as cactus, African violet or seed starting mixes. For outdoor containers, you will want a general mix. Some have additives such as fertilizer or moisture retaining polymers. Read the labels, try different types and see what works best for you.

Large containers can be extremely heavy when they are full of moist soil and plants. If you are using a very large pot, you can put packing peanuts in the bottom below the level you expect the roots to fill. Make sure that you use polystyrene peanuts; biodegradable packing peanuts made of starch will dissolve in water. Cover that with a piece of landscape fabric which is water permeable. Then fill the container with our soil till they are about 4/5 full, and water it to settle it in. You will add more soil after you have placed your plants. When all is done, it is very important to have at least 2” between the top of the mix and the rim of the pot to make watering easier.columnar-apple-trees

If, on the other hand, you have a relatively  small or narrow pot with a taller plant or bushier plant, you may want to make the bottom of the pot heavier to prevent it from toppling. If your arrangement threatens to be top-heavy, use gravel in the bottom of your pot instead.

My next post will be on selecting plants for your containers. So pick out your containers and get your potting mix and drainage material ready to go!