Friday, April 22, 2011

Perennial Preening

Slugs are the number one maintenance issue for PNW gardeners. I use a multiple phase strategy. First line of defense is iron phosphate bait which I try to put out twice a year, in April and October. Secondly, I go after IMG_0004individual perpetrators. I keep handy a spray bottle with 1/3 ammonia and 2/3 water and search for slugs in the cool of early morning or after a rain. It is worth it to pay the extra money for a sturdy bottle; I can hit a 4” slug at 20 paces. Last line of defense is the mollusk keg party. Use a small plastic container, such as a 6 ounce drinking glass, yogurt or margarine tub. Half bury in the soil and fill with the cheapest beer you can find. Read way more about slugs in this previous post.

Weeds will stage a coup and take control of your garden if not fended off. If you remove the weeds before planting and mulch after, your weeds will be manageable. 2-4” of mulch is plenty; it will also retain moisture and promote consistent imagesoil temperature. Many gardeners, especially in very cold areas, mulch in the fall to regulate the soil temperature and protect roots from frost-heave. Here in the mild PNW we don’t have a big problem with alternately freezing and thawing ground heaving plants out of the soil. 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.

Deadheading has nothing to do with rock bands and hippie vans. In gardening vernacular, deadheading is simply removing spent flowers. It keeps the garden looking fresh, promotes reblooming and prevents reseeding. Most plants will continue to bloom until they are allowedimage to set seed, so removing spent flowers encourages new blooms. Remove any dead leaves at the same time; some folks call this ‘dead-leafing’.

Pinching is cutting back all of the branches of the plant by 1/3 to 1/2 to promote bushier growth and more blooms. This is particularly effective with chrysanthemums and asters. I used to actually pinch these plants one branch at a time. I’ve learned that they respond just as well to whacking with pruners or even sheep shears. Thinning is a different process. To thin, remove 1/3 or more of individual stems of a plant to increase air circulation. This is commonly done with plants susceptible to mildew, such as phlox paniculata.

Staking is nobody’s favorite garden task. However, If you insist on growing imagedelphiniums you will have to stake-unless you grow the less common dwarf varieties such as D. ‘Blue Butterfly’ or D. nudicaule. If you must stake, do so early in the season so that the plant grows up gracefully around the stake. If you wait until the need becomes obvious, your plant will look like a hog-tied rodeo calf for the rest of the season. To reduce staking, use the right plant for the place. Not enough sun or too rich soil can make a plant leggy. Look for dwarf varieties. Pinching or cutting back will keep you from having to stake asters. Use supportive companion plants if possible. I sometimes use deciduous azaleas to support floppy late summer bloomers. DO NOT use a conifer to support another plant. Overlaying vegetation will cause damage or death to conifer branches.

During the season, and especially after frost, remove debris from the beds. Remember that anything diseased should be destroyed. If you leave it in the garden, you will surely see the problem again next year. Everything else can go into the compost for next imageyear’s mulch. You may also want to 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. Ornamental 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 chrysanthemums and fuchsias, they will overwinter more successfully if you leave at least 10” or so of growth. A great resource on maintaining your garden is The Well-Tended Perennial Garden by Tracy DiSabato-Aust.

Because our summers are dry, watering will be an issue. Be wise with your water. Thorough, infrequent watering will encourage deep root growth so imageplants can survive a dry spell. Avoid planting water hogs, unless you have a bog. Remember to choose the right plant for the place. Don’t plant a hosta in full sun. Given enough water, it will survive, but why waste the water and the time? Consider xeriscaping; once limited to places like Arizona, it makes sense to consider drought tolerance everywhere. Check out local examples like the drought tolerant section at BBG. High Country Gardens is a great educational tool about plants suitable for xeriscaping. Do be careful to avoid plants that cannot stand wet feet in winter if you are gardening in the Pacific NW. To determine if you have a problem, try this percolation test.

Division becomes necessary when bloom reduces or the center of the plant dies back. To keep the plants vigorous, you divide them and discard the center-with the added benefit of creating more plants.  You don’t have to wait for center die out; any plant that has grown larger than the place you have it planted may be divided. If it blooms in the spring, divide in the fall; if it blooms in the fall, divide in the spring. For more information, see this earlier post on division.

If all of this sounds like a lot of work, remember it is spread out over about 9 months. If you compare the investment in maintenance of perennials with the maintenance of a lawn, you will find that flowers are bargain.

2 comments:

  1. I am hoping you will write a new, fascinating, entertaining blog soon so I don't have to look at that slimy slug crawling across my Yahoo page!

    ReplyDelete
  2. Thank you for the encouragement! I've been spending all of my blogging time on http://georgefield.pathiwalked.com/ I will try to get back to Susiesgarden post haste!

    ReplyDelete