Preparing your garden for winter's chill
A surprising amount of activity goes on into winter.
Local news partner - Plant Talk
Valerie Easton writes in her blog about gardens and the people who make them.
GARDENING IS rich in satisfactions and ripe with myths, and nowhere do these two coincide more alluringly than in the idea of "putting the garden to bed" in autumn. There's such comfort in the delusion of nature slowing down so much we can just tuck in our gardens for the winter.
Leaves fall, perennials die back and annuals wither, yet a surprising amount of activity goes on into winter. Plants go dormant, but they continue to respire. Below ground (when it's not frozen solid) roots grow and repair. Weeds sprout, decomposition continues apace, and slugs and snails lay eggs; any creature that produces 40,000 offspring in two years of life is plenty cold-hardy.
My own fall routine is driven by finding yet more space to plant bulbs. I start by cutting back perennials that look so ratty I can't stand them, and those that have melted down to mush at first freeze. This opens up space to dig in narcissus and lily bulbs. Then I spread some mulch on top of any bare soil and around plants that tend to be tender. I keep up the slug patrols. I leave plants like coneflowers, asters and ornamental grasses alone until early spring to feed and shelter birds.
It's always a puzzle to know what to cut back when. We can rely on our usually mild and forgiving climate to cover for our mistakes in timing. Here's some more specific advice from Riz Reyes, gardener at the UW Botanic Gardens' Center for Urban Horticulture:
"I like to keep as many plants 'up' over the fall and winter months as possible to maximize visual interest," says Reyes. He waits until after the first hard freeze to cut back collapsed perennials such as columbine, Japanese anemones, brunnera, hardy geraniums, hostas, ligularia, phlox and herbaceous peonies.
When it comes to the soil, Reyes mostly just rakes and cleans it up in autumn. As for mulch, he prefers the well-composted, sawdust types mixed with manure, often called "fertile mulch." But he applies it in late winter or early spring before the plants emerge (you don't want to feed plants now). "A good, dark mulch helps plants 'pop' and be more noticeable in the landscape," he says. For plants that need cold protection, he mulches thickly over the crown with conifer boughs once the soil freezes slightly.
"Don't skimp on water; woody plants and perennials need to keep functioning to become completely cold hardy," warns Linda Chalker-Scott, associate professor and extension urban horticulturist at Washington State University. Moist soil is a better insulator than dry, and autumn mists can't be counted on to soak the soil.
Because deciduous trees and shrubs suffer less stress when dormant, Chalker-Scott advises waiting until the leaves fall to prune them. When it comes to mulch, she likes to use chunky wood chips laid at least 3 inches thick to discourage weeds and protect plant roots from cold.
And here's my favorite recommendation, because it plays right into how much I want to leave off gardening and shelter indoors once the weather turns. "Make an effort to keep as much organic material on your soil as possible, rather than discarding it," says Chalker-Scott. If leaves and debris aren't diseased, just leave them where they lie and mulch over the top. Your garden will look nice and tidy when you gaze out at it through the windows.
Valerie Easton is a Seattle freelance writer and author of "petal & twig." Check out her blog at www.valeaston.com. Susan Jouflas is a Seattle Times art director.