Washington is nicknamed “The Evergreen State” with good reason. How fortunate we are to have so many trees, both evergreen and deciduous. And what a challenge it is to garden beneath them!
If you’re a gardener who has more shade than sun in which to cultivate your own private Eden, don’t despair. There are many desirable plants with handsome foliage and flowers that flourish in the shade.
Let’s begin by defining the type of shade you’re blessed with. Is it beneath deciduous trees such as maple or alder, trees that lose their leaves in the autumn? Then your garden gets lots of light and moisture during the leafless half of the year, and your options are many. We’ll discuss them in a future column. Today we’re going to tackle dry shade gardening.
Warning: Dry shade gardening is not for the lazy. It requires dedication and tender, loving care. It’s much more of a challenge to garden beneath conifers (and under the eaves of your house) because these areas are generally too dark and too dry for most plants to thrive.
For decades, English ivy was the answer to the dry shade dilemma. It’s cheap, evergreen, and doesn’t require any care whatsoever. If there isn’t enough sunlight for grass, ivy will blitz over the entire back yard and into the neighbor’s, too. Problem is, this aggressive non-native plant likes the Pacific Northwest so much it escapes suburban yards and is taking over the forest understory, displacing native shrubs and wildflowers. It also misbehaves in the garden, clambering up trees and shrubs, eventually choking them out. And most disconcerting, English ivy harbors unwanted critters, including the Norway rat.
Once people learn — usually the hard way — that English ivy isn’t the answer, they discover how difficult it is to remove, with tough suckers that burrow into shingles and pry between boards. It’s gotten so bad that both Washington and Oregon have placed English ivy on their noxious weed lists. But it’s still around, even being sold in some nurseries. Please, don’t even think of using it in your garden!
Begin your dry shade garden by digging lots of compost into the soil to feed it and help retain moisture. Don’t pile a thick layer of compost or mulch around the base of trees. Rather, work it in or layer it lightly onto the soil. If you cut through small tree roots, don’t worry. Conifers are forgiving and the roots will regrow.
Choose plants that enjoy dry shade. If you’re leaning toward natives, salal and Oregon grape are naturals. For an airy or tropical look, choose ferns, such as male fern (Dryopteris filix-max), soft shield fern (Polystichum setiferum), or tassel fern (Polystichum polyblepharum). Native sword fern (Polystichum munitum) is also a good choice, but bear in mind that it can grow to four feet wide and high. We’ve planted several other varieties of fern in the dry shade woodland garden at Flying Frog Gardens. I’ll let you know how they do as time goes on.
A good ground cover for dry shade is Epimedium, sometimes called bishop’s hat. It has attractive, heart-shaped evergreen leaves, and delicate springtime flowers, ranging from cream to pink. Wild ginger (Asarum) is another ground cover with leaves like shiny green Valentines.
Add a shock of lime green flowers and evergreen foliage with Euphorbia amygdaloides var. robbiae. Wood aster (Aster divaricatus) will give you late summer blossoms, white fading to pink.
A small shrub that will add fragrance to the shaded winter garden is sweet box (Sarcococca hookeriana var. humilis). This modest little broad-leafed evergreen has tiny white flowers that don’t look like much, but give off the delicious scent of honey vanilla in January or February.
There are many more plants, native and non-native, that will thrive in dry shade, once established. I don’t have space to list them all. Visit the shade sections of local nurseries; you’ll be surprised. I also invite other dry-shade gardeners to write in and share their favorites.
Now that you’ve chosen plants and prepped the soil, settle them in and water frequently and deeply until they’re comfortably established. Then check daily to make sure they have enough moisture, especially if planted under Douglas fir, which sucks vast quantities of water from the soil. If you’re planting now, don’t fertilize. Wait until spring to use a water-soluble, acid-type fertilizer.
Gardening under evergreens is a challenge, but with care, your garden can be successfully made in the shade.
August checklist
Don’t let your garden dry out! Provide your plants with a minimum of an inch of water per week, more during hot spells. The best time to water is early morning.
Use mulch to protect roses and other ornamentals from hot weather damage.
Prepare your vegetable beds for cool weather crops by working in slow-acting organic fertilizer and composted manure.
Early in the month, plant cool weather crops such as spinach, lettuce, chard, cabbage, mustard greens, kale, arugula, onions, beets, carrots, turnips and rutabaga.
Fertilize cucumbers, summer squash, beans, peas and broccoli, while harvesting to maintain production.
When garlic stalks begin to yellow, dry out and flop over, it’s time to harvest. Brush off loose soil and hang from foliage in a dry location with good air circulation.
Keep perennials and annuals flowering through regular deadheading. Let a few seed heads dry and collect them to sow for next year’s flowers.
Pinch back chrysanthemums to keep them from getting leggy. You’ll have stronger plants with more blooms in early fall.
E-mail Island County Master Gardener Mariana Graham at frogardn@whidbey.net.