By Molly Day
If you have a tree, shrub row or a building on your property, you have dry shade. Shade created by a fence, an overhanging roof or a wall often has enough light several hours a day to make many plants grow. The shade under a tree, however, can last all day, and the tree’s roots can steal all the water, making it difficult for flowerbeds to thrive.
Fall and winter are a good time to take on these areas. The drought seems to be behind us and it is easier to work outdoors in cooler temperatures. Perennial plants (those that live more than one year) can be planted with success until the ground is frozen.
If you are adding trees to a landscape, choose those that allow sun to filter down to the ground. Trees that produce dense shade include maple, beech and magnolia. Trees that allow sun to penetrate to the soil include paperbark maple, dogwood, birch, white beam and ginkgo.
Some of the best shade trees to plant if you want grass and plants to grow underneath them are: paperbark maple, paper mulberry, Kentucky coffee tree, Gondenrain tree, black locust, Japanese pagoda and Himalayan whitebeam.
It is relatively easy to increase the sunlight to plants under trees by removing the lowest limbs and pruning some branches. Thin out scrawny trees that add nothing to the appearance of your yard.
To increase the amount of moisture for plants under trees, you can replenish and improve the soil, put in drip irrigation or mulch the entire area to hold the moisture longer.
Once the soil and the growing conditions are improved, it is time to select suitable plants for those shady spots.
Graham Rice, the author of “Planting the Dry Shade Garden: The Best Plants for the Toughest Spot in Your Garden,” says that these plants should be ones that:
• Lose less moisture through their leaves than most
• Have roots, rhizomes, tubers, or stems that store water.
• Are able to thrive in low light
• Are evergreen and can take advantage of light in any season
• Come out early in the season so they collect light before the leaves emerge on the trees
At this time of year, tucking bulbs under trees is a natural. Early blooming bulbs will flower before the trees leaf. The ones to plant include: snowdrops, winter aconites, glory-of-the-snow, miniature daffodils, wood anemones and squills. We put 300 little grape hyacinth and crocus bulbs under four trees this fall.
To create a nice appearance, you can plant perennial ground covers in dry shade.
Epimedium is a popular, flowering, perennial that grows well under shrubs and trees. It grows about 1 foot tall and has no trouble competing for moisture. The dry-shade tolerant varieties are: Epimedium perralchicum, Epimedium pinnatum colchicum, Epimedium perralderianum, Epimedium versicolor, and Epimedium warleyense.
Hardy Geranium is another good choice. They grow about 1 foot tall and form thick, woody-stemmed clumps that flower. The varieties that will work best include: Geranium cantabrigiense, Geranium endressii, Geranium macrorrhizum, Geranium nodosum, Geranium oxonianum, Geranium phaeum and Geranium versicolor.
Another option is evergreen Sweetbox. The low-growing varieties for under shade trees are: Sarcococca hookeriana humilis (18 inches) and Sarcococca ruscifolia Dragon’s Gate (2 feet).
Universally recommended Mrs. Robb’s Spurge (Euphorbia amygdaloides robbiae) is an evergreen perennial with chartreuse flowers.
“Planting the Dry Shade Garden” by Graham Rice, published 2011 by Timber Press, www.timberpress.com or (800) 327-5680. The price is listed at $25, but you can get it online for $17.
The photographs in this 190-page softcover are worth the purchase price. They will inspire you to use the cool of fall and winter to rehabilitate your shady garden spots.