Dear Miss Floribunda,
I’ve moved into a nice old house with a good-sized backyard that would have great possibilities if the former owners hadn’t haphazardly planted all their Christmas trees in it.  Nothing seems to grow under the evergreen canopy except holly. Though I am not as ecologically responsible as people who buy live trees and plant them after the holidays, nonetheless I don’t want to cut down what are by this time old trees that I feel have seniority over me. I planted the usual impatiens but they have already died. I don’t much like hostas, and would really like some summery color and fragrance to enjoy when I sit outside.  What do you suggest?
Christmas in July on Jefferson Street

MISS FLORIBUNDA —
Dear Christmas in July,
The evergreens present you with a triple challenge: shade, extreme soil acidity and a drain on soil moisture from the tree roots.  You don’t say whether you have pines, firs, spruces or all three. Pines are generally high-shade trees that permit some things to grow beneath them. You can limb Douglas firs, lopping off the lower branches, and if you have the strength and skill, create some interesting shapes with other conifers by limbing, topping and pruning.  I’m tempted to suggest you go for a Japanese garden, made aesthetic with sand and stone, as well as plantings of re-blooming
camellias and azaleas where there is enough moisture for these. However, you make it plain you would like a traditional summer garden.
There are daylilies that tolerate at least partial shade and they do not require a great deal of water. Oakleaf hydrangeas could be combined with these, if you are willing to keep them well watered and fertilized. You might try a soaker-hose system. For fragrance, the hay-scented fern (dennstaedtia punctilobula) is known to grow beneath pine trees and needs little water. It spreads too.  Hellebores and various wild flowers come to mind, but they are all spring-blooming.
A particularly fragrant shade-loving ground cover, though nominally a spring-bloomer, is the lily-of-the-valley. The perfume is intoxicating and it blooms in May, which in our region is warm enough to invite sitting outside in the garden.  Though you seem not to care for hostas in general, you might be susceptible to the charm of a Southern favorite called the August lily (hosta plantaginea). It thrives in our area and its showy white blooms have a delectable fragrance much like honeysuckle. They show up very well in shade and their icy luminosity visually cools off a hot late-summer evening.
Probably the easiest and quickest thing you can do is bury pots of begonias and impatiens around the trees and take them in before frost.  There are really ravishing varieties of these, in every color and shape. They tolerate shade well but can handle only a certain amount of soil acidity. They need plenty of moisture, but you can water pots of them as needed rather than continuously through a soaker system. You could mix beautiful blue lobelia with these, or create a tapestry of coleus, the color of which intensifies in shade. There is some chance you could grow coleus directly in the soil, but it is not cold-hardy so you might as well keep it in pots. You can take them in and propagate plants for the coming year from them from cuttings. Few things root more easily than coleus in water.
To discuss this and other topics with members of the Hyattsville Horticulture Society, please come to our next meeting at 10 a.m. on Saturday, July 16, at the municipal building.