Monday, April 26, 2010

Epimedium? Well Done!

IMG_0068 If you have discovered the versatile and lovely Epimedium, lucky you! If not, you are in for a treat. A member of the barberry family  (Berberidaceae), it has the same tough, sturdy nature as its relatives such as Mahonia and Vancouveria, both of which are native to the Pacific NW. Epimedium is commonly called barrenwort, fairy wings or bishop's hat.

Although often described as an excellent ground cover, this is only true for those few species that spread by elongated rhizomes. All Epimedium spread by underground rhizomes but in most species the rhizomes are short and the plants form dense clumps. Varieties native to the eastern Mediterranean tend to be drought tolerant and spread steadily by rhizome; those native to Asia tend to require more moisture and are best grown as isolated clumps.

Epimedium species have little vulnerability to pests or diseases and are easy to grow. Most are native to woodland habitats so they thrive in light shade or morning sun in well-drained, moist, fertile soil. (Doesn’t almost everything?) The Mediterranean varieties can take more sun, especially here in the Pacific NW. Remember that even the drought tolerant varieties will need regular water for the first year after planting.

If you have evergreen cultivars, you don’t want the dainty flowers struggling to compete with last year’s tatty foliage. You will have to figure out when the flower stems emerge so that you can cut the foliage to the ground before there is a risk of cutting off new flowers along with old leaves. For example, in my garden the time to cut back the evergreen E. perralchicum is in January. Then the flower stalks will appear first and lush new leaves will emerge below them.

Epimedium × versicolor 'Sulphureum', is drought tolerant once established and spreads vigorously enough to be an effective ground cover. The delicate yellow blooms look just like racemes of tiny daffodils. The leaves are flushed red, especially in the spring and in the fall and the foliage grows to about 12” tall. Epimedium x perralchicum

Epimedium x  perralchicum  'Frohnleiten'  is equally sturdy with more vibrant yellow flowers and more flushing on the new leaves. This variety grows in full sun with little extra water and blooms in February in my PNW garden. It is a vigorous but not invasive spreader.

Epimedium × warleyense produces evergreen leaves topped by stalks of flowers in coppery red and yellow. These plants will spread, but more slowly than E. versicolor and E. perralchicum. The cultivar 'Orangekönigin' (Orange Queen) has a slightly paler bloom and is a Great Plant Pick. This plant blooms for me in late March to April.

Epimedium grandiflorum ’Lilafee’ produces racemes of long-spurred, lavender-violet flowers in spring well above the foliage, which is deciduous in climates colder than Zone 7. E. grandiflorum is a bit larger-to 15” or so-and is native to Japan. It forms a tidy clump and is not considered a ground cover.

IMG_0067Epimedium youngianum‘Niveum’ is a dainty variety that grows to 6” tall and 12” wide with pure white blooms in May to June. E. youngianum is thought to be a hybrid between E. diphyllum and E. grandiflorum. The original plants were brought from Japan to Europe in the 1830’s.

Epimedium are lovely with other woodland dwellers. For example, Heucheras come in a wide variety of foliage colors and are persistant through the winter. Think Heuchera ‘Marmalade’ with E. x warleyense 'Orangekönigin'. That’s what I’m talking about. Helleborus provide a nice foliage contrast and bloom in winter, just before some varieties of Epimedium.  Other possibly concurrent bloomers are spring ephemerals, such as Trillium and Erythronium. Also, daffodils and other naturalizing bulbs are terrificE. youngianum 'Niveum' companions as the larger Epimedium varieties provide excellent cover for their fading foliage. Ferns of all kinds are an excellent textural contrast. A vignette I particularly enjoy combimes E. youngianum ‘Niveum’ with Hostas, Blechnum spicant and the tiny, frilly Aruncus aethusifolius.

To propagate Epimedium, lift clumps in early spring or early fall and divide them with a sharp knife. Replant each division in well-draining soil amended with compost, and keep them moist while they settle in. Because, really, you can never have enough epimedium!

Thursday, April 22, 2010

April Showers

Actually, in the Seattle area the showers come September through July. We tend to have a very dry summer but it generally begins after July 4 and is frequently fades away before September is over.  Of course, the only thing reliable about weather predictions is that they are never reliable, so there you go. When I do get out there I have been potting and delivering plants for the Master Gardener Plant Sale at McCollum Park in Everett on May 1. I've delivered about 550 plants and have about 200 left to go.

I have a particular spring vignette that I love that doesn't even include blooms. I've planted Physocarpus ‘Coppertina’ Photo0199 with Spirea 'Goldmound' and Heuchera 'Marmalade' and the grouping just pops against the dark brown of the compost mulch before the perennials emerge.  It is very satisfactory. I suppose it helps that bright blue Veronica peduncularis ‘Georgia Blue’ is beginning to bloom right in front of all that orange!

The Rhododendrons are still putting on a big show. Believe it or not, R. ‘Taurus’ is still blooming down in the woodland. The blue rhodies are fabulously beautiful. Many of these-such as R.  ‘Blue Diamond’ and R. ‘Ocean Lake’-are descendents of RRh. Blue Diamondhododendron augustinii. Augustine Henry was a Medical Officer with the Imperial Chinese Customs Service on the Yangtse river. He was instrumental in preserving and transporting new Rhododendron specimens collected in China by the French missionaries to Kew Garden in Great Britain. R. augustinii was named after him at Kew.

Lathyrus vernus is a perennial sweet pea that is not a vine. This well behaved, long blooming plant has had flowers in shades of magenta, blue and purple for over a month. The Brunnera, mentioned as blooming last monBrunnera Hadspen Creamth, is still sporting lovely forget-me-not poseurs.  From the same family as Brunnera (Boraginacea), the Pulmonaria has also been flowering for about six weeks. P. ‘Roy Davidson’ has blue and pink blooms on the same plant, along with silvery variegated foliage. P. ‘Blue Ensign’ has outstanding flowers of dark royal blue with silver spots on the leaves. P. ‘Silver Streamers’ has classic pink-fade-to-blue blossoms but the real draw to this variety is the almost fully silver foliage. P. rubra has salmon pink blooms.

I love the Pasque flower for its unique foliage, flowePulsatilla vulgarisrs and seed heads. Pulsatilla vulgaris may bear flowers in purple, red, or white, but the frilly foliage is the same in each case.  As an added bonus, the flowers turn into fluffy, silvery seed heads that persist all summer. On this plant, I like the seed heads as well as the flowers!

When I started gardening, I thought that I didn’t like Bergenia, and not just because the common name is pigsqueak. Bergenia has lovely pink or white flowers on a stalk in early spring, but my favorite thing about this species is the thick evergreen leaves that turn ox blood red in the winter. Not all varieties have equally fine winter color, so try to acquire yours while in their winter dress. They also make a great container plant for the forgotten season.

Speaking of interesting names, Ranunculus ficaria ‘Brazen Hussy’ is a favorite. Unlike the species, this variety of Ranunculus is not weedy. In fact, you may have to pamper it just a bit to get it going. This ephemeral emerges in February with glossy bronze foliage in a rosette just 6" high. In early spring, the clumps are topped with small but brilliant yellow flowers just 3" above the foliage. The contrast between the dark foliage and the yellow bloom is, well, brazen. This particular Hussy goes dormant by May, so be sure and mark your clumps so you don’t accidentally dig into them before next spring.

Sunday, April 18, 2010

Workhorse Roses

Through much trial and error, I have found a few roses that I consider to be workhorses in the PNW.  These are roses that are disease resistant, hardy in our zone, with an appropriate mature size for their space in the garden and long bloom or repeat bloom. I’m sure there are many more that would make such a list, but my space is limited. Most of my garden is in part to full shade which is a deal breaker for most roses

garden 009 Rosa ‘Just Joey’ is my only hybrid tea and probably my favorite rose. What a beauty! The disease resistant foliage emerges burgundy and gradually fades to a darkish green. The tightly formed buds are deep apricot and open to an exquisite, fluffy blossom 6” across. The open bloom is a paler apricot with deeper tones at the base of the petals. It blooms early summer and then reblooms in the fall. Wherever I garden, I will have to have ‘Just Joey’, it is that good.

Rosa ‘Zephirine Drouhin’ is a lovely cerise pink Bourbon rose with a fragrance that can be detected 10’ away. This rose is noted for its shade tolerance but best flowering and disease resistance are in full sun. This can be grown as a climber to 12’ or kept pruned to about 6’. It is nearly thornless which makes it a great candidate for an entryway or walkway.

Rosa ‘Iceberg’ is a floribunda rose that was introduced in 1958 and has an ARS (American Rose Society) rating of 8.9. Double flowers have a light and pleasant scent. Blooms are long-lasting and truly white, not ivory or pale pink. It has good disease resistance.Beckypictures2 008

Rosa ‘Golden Celebration’  is another selection with beautiful, healthy, disease resistant foliage, this time deep green. This rose opens golden and fades to a paler yellow but is always beautiful with a luscious lemony scent. It blooms all summer and looks stunning with a Clematis durandii scrambling through-which also blooms all summer-a winning combination.

Rosa ‘New Dawn’ is a dainty double shell pink rose that is a vigorous climber to 10-15’. It is disease resistant and tolerates poor soil and partial shade, although it will be healthier and more floriferous in sun. The blooms repeat summer through fall. I have this scrambling through a Kolkwitzia amabilis along with Clematis ‘Hagley Hybrid’ and Lonicera periclymenum ‘Harlequin.’ Good thing the beauty bush gets 10’ tall and wide; it’s got a lot going on in there.

Flower Carpet Roses: Easy-care, low-maintenance, fast-growing and flowering continuously from early spring to late fall. These lovely plants are full and densely-branched to 2-3’ tall and 4-5’ wide. They are not divas; tolerant of varying soils, will bloom in part sun, disease free, they thrive in Zones 5-10. Developed in Germany after 30 years of work and introduced in 1995 to much fanfare. They now come in nine colors and look fabulous singly or in masses of color. Prune these hardworking beauties back to about 1/3 its size in early spring.

Rosa ‘Hot Cocoa’: it is impossible to do justice in describing the color of this floribunda rose- sort of rust red with chocolate and smoky orange overtones? You’ll have to trust me, it is a stunner. The thick and velvety petals form a flawless flower which is durable in arrangements. The unique flower color, strong healthy foliage and sweet, spicy scent make this rose a winner. If deadheaded, it will bloom all season. It took top AARS (All American Rose Selection) honors the year it was introduced-2003. Since 1940 the AARS awards represent the world's most exacting rose trials. Candidates are grown for two years in 22 public trial gardens as well as in the trial gardens of 14 US rose industry leaders who are AARS members.

Rosa ‘The Fairy’ is a polyantha rose with profuse clusters of small but frilly double pink flowers. Though not fragrant, the blooms appear in waves from May to frost. This plant has good disease resistance and tolerates poor soil and shade. Vigorous and compact (about 2’ tall and wide) it has glossy, small leaves and tiny but plentiful thorns. In late winter or early spring, prune hard (back to 10-18 inches) and reduce side shoots to 2 or 3 buds. To renovate, prune one in three stems close to the base.

These are not listed in any order except the order I thought of them. Each of these roses is a dependable, sturdy performer that you will enjoy.

Thursday, April 15, 2010

Roses for the Pacific NW

My garden is pretty large (and seems to get larger all the time) so I am starting to truly appreciate plants that are low maintenance. That being said, I must confess…I love roses! Their color, fragrance and increasingly blowsy beauty as the flowers expand are without equal. The trick to easier maintenance is to find, if possible, roses that are suited to your own garden.   Rose characteristics to consider would include disease resRosa Violettesistance, mature size, cultural requirements, season of bloom, color that will compliment your garden, and fragrance. You must also consider your own characteristics. How much patience do you have for plant divas? What is your stance on chemicals in the garden?  How averse are you to pruning? In February?

If you choose to put your money on one of these lovelies, make sure your site has good drainage and at least 4-5 hours of sun. If you don’t have full sun, your rose options are limited and if you have mostly shade, you will need to enjoy your neighbor’s roses, because they aren’t going to grow in your garden. (Perhaps you can barter some hydrangea blossoms for your neighbor’s cut roses!)

Water regularly and deeply; frequency will vary with weather conditions.  Soaking is better than sprinkling; if you overhead water, finish early in the day to provide time for the leaves to dry completely. It is a good idea to provide good air circulation and remove fallen leaves to help prevent disease.

Keeping 2-3” layer of compost mulch over the root zone of roses year round will help keep soil moist and cool during summer, prevent frost heave in winter, and lessen soil compaction andRosa Sterling Silver weed growth.

Prune established hybrid teas and floribundas around Presidents Day,  removing dead or small twiggy growth, leaving 3-5 strong healthy canes to a plant height of about 18”.  Try to prune back to an outward facing bud to maintain spreading, open growth. 

Don’t prune climbers until after the heavy spring bloom, then remove only the oldest canes and cut back the healthy, vigorous canes no more than 1/3.  Remove spent blooms throughout the season from all rose varieties, cutting back to the first 5 leaflet cluster.

Some rose growers are strong advocates for using Epsom salts, claiming improved plant health and stronger growth. If you want to try this, either mix ½ cup of Epsom salts into the soil around the rose bush and water well or dissolve ½ cup of the salts in water and use to water the rose bush. Do this in the spring, just as the buds are beginning to open. Epsom salts are magnesium sulfate; both magnesium and sulfur are important trace minerals for plants. For optimum growth, roses need high levels of magnesium which tends to be lacking in the Pacific NW.  Testers have reported greener foliage, bushier plants and more blooms with Epsom salts over control plants.

The only pest I encounter on my roses is aphids. My quick fix is to spray them with a sharp stream from the hose. My long term solution is natural predators; my favorite is the hummingbird. Anna’s hummingbirds overwinter in our area so they are always on patrol. They eat a prodigious number of aphids and other pests-such as mosquitoes. Attract them to your yard by including plants they favor in your garden and putting out syrup for them.

Some gardeners prefer to put their roses together for ease of spraying and pruning. One disadvantage to creating a rose clique is that you set out a smörgåsbord for serious rose pests such as Japanese beetles. With so many host plants together, your pest population is likely to skyrocket. Similarly, diseases like black spot spread from one rose to another, so if they are close together, it is harder to control.  I preRosa Just Joeyfer not to use chemicals on my roses and I have a limited number so pruning is not a chore. I like to scatter my roses among the other shrubs and  perennials in my mixed borders. It is comparable to choosing between a dozen roses or a mixed bouquet, both are lovely.

If you have enough sun and enough patience, run for the roses. They are worth the trouble!

Friday, April 9, 2010

Woodpecker Wars

One morning, I woke up thinking our neighborhood was under attack. There was a deafening uproar like a particularly metallic-sounding Uzi. We leaped out of bed, but couldn’t immediately determine the source of the noise. The culprit turned out to be a woodpecker. Not being wise to woodpecker wiles, I thought, “He’s not going to find much to eat on that metal chimney flashing.” Actually, he was “drumming”-hammering loudly on a resonating surface to create noise, kind of like a heavy metal musician and for a similar reason. Since woodpeckers do not have a song, they use drumming as a territorial signal and to attract a mate. This goes on mostly in the spring and, as I can attest, in the early morning.

Most woodpeckers forage on tree bark, although Northern Flickers can be found feeding on ground insects such as ants. Woodpeckers have specialized beaks, long tongues and unique clinging feet with 2 toes directed backward to help the bird grasp branches and trunks. They move up a tree by hopping; they depend on their stiff tail feathers to support them. The woodpecker’s tongue can be as long as the woodpecker itself. I am not making this up.

Not all woodpeckers seek insects for food. A sapsucker is a woodpecker that prefers sap. This tricky character will also eat insects attracted to the sap. The United States Forest Service (see page 8) has determined that the yellow-bellied sapsucker kills trees. This bird is a serious tree pest and, being migratory, it affects trees throughout North America.

I’m not the only one to be perturbed by these pesky perpetrators; the Cornell Lab of Ornithology received so many pleas from harassed homeowners that they sought a grant to study the “ecophysiology and behavior of woodpeckers in suburban areas.”

Woodpeckers are beneficial when they eat harmful insects, but when habitat is scarce they can cause severe damage to wooden buildings and ornamental trees. Woodpeckers drill holes when drumming, to forage and to  build nesting cavities.

Woodpeckers roost and nest in cavities only slightly larger than the width of the bird. They prefer dead trees or snags that have a hard outer shell and a softer inner cavity, but some seem to find the soft cedar siding of houses to be ideal. So, once their drumming has paid off, they start excavating your home to make theirs.

If you want to minimize damage to your house or trees, once you are onto the woodpecker’s plan, you should take immediate action. Once established, they are not easily driven from their territory. There are multiple suggestions for deterrents and the best course of action may be to use more than one technique simultaneously. Use your chosen control for at least 3 days before switching to something else.

The most effective solution may be to exclude the birds from the area or tree at risk. Put hardware cloth, plastic netting, or metal sheeting around trees or on siding. Paint the materials to match the siding or tree color. Protect sites under the eaves by attaching hardware cloth or plastic netting to the eaves, angling it back and fastening it to the siding below the damaged area. If there is a specific landing site, tightly stretch heavy monofilament fishing line or stainless steel wire across it to exclude the bird.

You can make a deterrent from aluminum foil, which may be the most effective visual repellent. Cut strips of several inches wide and about 3 feet long. Attach one end of several strips to a 6-8 inch string. Nail small brads 2-3 feet from the damaged area. On a building, place the brads 6-10 feet apart. Attach each string to a brad so that the foil strips hang freely and move with the breeze. Sticky repellents like Roost-No-More®, Tanglefoot® and Bird Stop® can also be effective when smeared on the trunk and branches of high value trees.

Discourage drumming on the house by filling the hollow space behind the chosen area to deaden the resonance. Use a can of expanding foam insulation which you can spray into the hollow area. This can be purchased from hardware stores. Existing holes may serve as visual attractants. Promptly cover holes with aluminum flashing, tin can tops or metal sheeting, and paint to match the siding to discourage return visits.

It is against the law to kill a woodpecker without the proper permit because they are migratory birds and are protected by the Federal Migratory Bird Treaty Act. The permit requires proof that you have used other measures and that they have not been effective. Penalties may include fines as high as a $500 and 6 months in jail. Killing a red-cockaded woodpecker carries an even stiffer fine and jail sentence because is a federally endangered species.

For a description of the mayhem which ensued when a hapless West Seattle homeowner attempted woodpecker reprisal, read this blog entry. Try to win your war for peace by non-lethal means!

Sunday, April 4, 2010

Great Plant Picks

Great Plant Picks (GPP) is an educational plant awards program originating from the Miller Garden that recommends outstanding plants for the maritime Pacific Northwest. The garden is known for its exceptional collection of fine trees and shrubs and an expansive variety of woodland herbaceous perennials.

Elisabeth Miller was very interested in horticultural education and she Athyrium niponicum var. pictum  Photo by Aleta Mueller founded the Elisabeth C. Miller Library; it seems very natural that the public garden she endowed would be the originator of this exciting program to educate the public about terrific plants ideally suited to our area.

GPP was started 10 years ago to select and promote plants that are: hardy in USDA zones 7-8; are relatively long lived, vigorous and easy to grow; are reasonably disease and pest resistant; and have a long season of interest. The plants are divided into Perennials and Bulbs; Shrubs and Vines; and Trees and Conifers. Each division has a selection committee made up of industry experts: retail and wholesale nurseries, public gardens, landscape professionals-all from western sections of WA, OR and BC.

Assisting the Selection Committees are Advisory groups that focus on types of plants that require more specific experience to evaluate: ferns, Rhododendrons and roses.  As part of the selection process, members meet with subject experts and visit public and private gardens throughout the Pacific Northwest for field evaluations.  Some evaluation reports are available on the GPP website if you’d like to see how the process works.

Every year an eagerly awaited list comes out,  usually in conjunction with the NW Flower Epimedium × perralchicumand Garden Show in February. To date, over 800 exceptional plants have been selected for gardeners living west of the Cascade Mountain range from Eugene, Oregon to Vancouver, British Columbia.

This year, some care was taken to fill in some of the gaps perceived in the list, such as bulbs and grasses. In addition to their new picks for 2010, Great Plant Picks presents ‘Fantastic Foliage’, a selection of plants with exceptional foliage gleaned from the last ten years of award-winning picks. The program hopes to assist the public to choose from all plants selected over the past 10 years by providing different ways of categorizing them.

The GPP website is a treasure trove of useful information on these plants; each plant has its own page listing itsAcer shirasawanum ‘Aureum’ outstanding qualities, cultural requirements, growth habit and, in most cases, at least one photo. If you are interested in any plant, you can print a fact sheet for future reference. You can print the entire list of almost 800 plants-be warned it is 17 pages. You can also search the plant lists for a keyword, such as “berries” and print the resulting list (43 plants!)

If you happen to be lucky enough to live in the lovely Snohomish County, watch for completion of GPP focused mixed borders now being renovated by Master Gardeners at both Jennings Park and Legion Park Demonstration gardens.

If you are looking for the perfect plant, renovating a garden or starting from scratch, check out Great Plant Picks. It is an extremely valuable tool for PNW gardeners.

Thursday, April 1, 2010

Divide and Multiply

Would you like to have more plants for free? Now is a good time for dividing herbaceous perennials that do not bloom in the spring or early summer. Actually, it would not hurt spring and summer bloomers to divide them now, but you would probably sacrifice this year’s flowers. If you have plants with center die-out, plants that have outgrown their space or whose blooms are decreasing each year, it is time to dig them up.

Remember that disturbing the root system hinders the plant from taking up necessary nutrients and water. Soaking your plant well, preferably the day before you intend to divide, will reduce the trauma. If your plant has a lot of top growth, you can also reduce shock to the roots by cutting back the leaves by about 1/3. It is a good idea to have the holes prepared for your new plants before you dig up the original plant to limit the time the roots are exposed. 

That being said, I once left a huge hosta sitting on top of the ground all winter. Ooopsie. Unbelievably, when spring arrived, it put out luscious new growth and I split that puppy up and had a bunch more incredibly vigorous plants. That would not happen just anywhere; remember, I live in the moist and magical Pacific NW.

Dig up the plant you wish to divide and try to get a majority of the root ball. Divide the plant into new plants that are large enough and have enough roots that you don’t have to baby them but not so big that you will be back dividing the divisions next year. Some people use two pitchforks back to back; the idea is to insert them through the crown of the plant and then push the two handles away from each other. Sounds easy; I don’t have two pitchforks.

I divide most of my plants by digging them up and slicing through the crown and/or root ball with an old kitchen knife. You have to be very careful no matter what you use. If you go the pitchfork route, they can send you flying if you suddenly break through or if the tool itself breaks on a particularly difficult root mass. I once dropped my knife and it landed, point down, in the top of my foot. Went to the walk in clinic for a tetanus shot. Gardening can be dangerous if you are a klutz.

If the plant is too large, you can use a saw to divide the root ball. This doesn’t happen often in my garden because I’m constantly dividing plants. In fact it is a subject for amusement to my husband who cautions me to never buy a plant that doesn’t come with its own little suitcase, because it is bound to spend its life traveling.

Some plants may be divided in situ; once you are familiar with the Hakonechloa and Geranium underground structure of your plants, you will know which ones can be divided by merely choosing the right place and slicing straight down with your shovel and popping a division up onto the surface. Hardy geraniums (not pelargoniums), hostas, daylilies and some grasses, such as Hakonechloa, are examples of likely plants for shovel division.

As noted in my previous blog, plants are best divided when not in bloom so that all their energy can go to root and leaf growth. A moist, cloudy day, ideally followed by several days of gentle rain is preferable for all kinds of planting, including planting divisions. True confession: I have been known to dig up and move a rose in full bloom in the middle of our dry Mediterranean summer and have it live. It was a near thing, though.

If you have no other option but to plant on a hot, dry day, try “puddling in” as the Brits have it. Wait to expose your plant’s roots till the hole is ready. Dig the hole and fill it with water. Let it drain and fill it again. You want the surrounding soil to be saturated.  Dig your plant, replant and cover the root ball immediately. Form a soil dam or collar around the rim of the planting hole and water again. If necessary, and it probably is, rig some shade for the plant.

Speaking of water, remember that even drought tolerant plants require moisture until they are established. Now, get out there and make plants!