Marianne Binetti

Marianne Binetti: As soil warms, think about creating a shade garden

The end of March is a great time to add trees, shrubs, perennials and vines to the garden. The soil is warming up, but most plants are still a bit sleepy from winter dormancy so they don’t mind being transplanted this time of year.

Here in Western Washington we have an abundance of evergreen trees and lots of shade. Add to that our plentiful overcast days and many gardeners struggle to add color to areas of dry shade. Cedar trees are the worst for sucking the moisture out of soil and creating garden areas where nothing attractive wants to grow.

Here’s a suggestion work with what you’ve got. Consider looking at shade as an asset and landscaping in dry shade as the art of blending native plants, tough groundcovers and accents that even cedar tree roots can’t kill.

Landscaping in Dry Shade

There are different degrees of shade and dry soil. These plants all survive with at least a few hours of sun a day and some water to get them established. Watering new plants in dry shade is especially important during that first summer season as the roots become established.

Start with something tall — native vine maples or dogwoods fit into a wooded area of native cedar and hemlock with ease — but if you have enough space free of tree roots you can also add Japanese maples or even a tall evergreen, such as the shade-tolerant Yew.

You can make a bold splash in dry shade by adding an evergreen shrub called Japanese Aralia or Fastia Japonica. Large shiny leaves give it a tropical look. Another broad leaf evergreen for dry shade is Aucuba, especially the gold spotted cultivar called “Mr. Goldstrike.’

Both Fastia and Aucuba were popular shrubs near shaded front-entry areas in the 1950s before those bold foliage shrubs fell out of fashion. Nurseries are once again selling these two drama queens because not only do they light up the darkness with bright foliage, berries and blooms, but they do this without demanding a lot of drink.

Next add some mid-height blooming perennial plants. There are not many perennials that can compete with the tree roots of cedar, fir and hemlock, but if you add six inches of topsoil or compost and work it into the soil, you can enjoy hardy cyclamen, Japanese anemone, euphorbia, hosta and, surprisingly, a peony or two. The key is to baby the new plants for the first year until they establish their own thick root system to compete with the trees. A quick shortcut is to cover the ground under large trees with wood chips. Then set some pots on top of the mulch and grow flowers in containers. Impatiens, begonias, lobelia and fuchsia will all bloom in the shade — but do not expect these annuals to compete with tree roots. They are best grown in pots or a raised bed around large trees.

Finally, fill in the floor of the woodland garden with groundcovers. If you fear aggressive groundcovers but want to avoid weeding any open space in a woodland or dry shade garden, then consider using Vinca minor, creeping Jenny or, my personal favorite, lamium as a colorful carpet. These groundcovers will become a growing nuisance in any soil that is fertile or moist, but in dry shade they will slowly spread to smother weeds and hide fallen debris. Don’t be afraid to cut them back or even use a string trimmer to remove old or tatty foliage of established groundcovers in the spring. Cutting the tops off of groundcovers and then adding a thin layer of cow manure, bark chips or topsoil is a good way to renew these plants no matter where they grow.