Dear Garden Problem Lady


 Now that April’s here my Knockout Rose is sprouting. This rose was far too big for its space last year, but I forgot to prune it last fall or in March. Now that I have missed the pruning window, will I damage the shrub by pruning this late?
You are correct about the pruning window for old roses which bloom on last year’s wood. But Knockout is a shrub rose. You can remove as much as a third to one-half of the plant’s overall volume, as long as you do it early enough for it to grow back. First remove dead or overlapping stems, and, later, any growth spurts that shoot up if they spoil the overall rounded shape of the plant.

My irises sporting fresh new leaves, poke above the many accumulated dry tree leaves over and around them. When I brushed those dry leaves away I see a great many of the iris roots are above ground too. Beige in color. These irises are quite a few years old. Should I add more earth?
On no account should you add more earth. Iris roots need to be half above ground. Otherwise the plants won’t bloom. Your old irises have survived perfectly just as they are.

We need some flower that can cascade and drape up – or down – over a fence. Suggestions?
Does sun shine on your fence? If it has good sun, almost any annual vine will provide you with color – but don’t try to grow an annual from seed this late. Seeds must start early, indoors under lights. Look for the following as seedlings: Morning Glory (try Heavenly Blue), Moon Flower vine (not “Moonflower”), Sweet Pea, Nasturtium Vine, Cardinal Vine, Scarlet Runner Bean, Black-eyed Susan vine and Cup and Saucer Vine.

If you would prefer a perennial, try Clematis, which is best planted in spring after all danger of frost. It too prefers sun, but likes “cool feet”, meaning that the root must be dug very deep, and its base shaded by other plantings.

How can I make an orchid bloom again?
Cut off the old flower stalk and put the plant where it can be ten degrees cooler at night than in daytime – perhaps by a cold window. No direct sunlight — in nature orchids live under trees, get only filtered sunlight, and need very high humidity. Therefore, place the pot over pebbles in a pan filled with water. Fertilize twice a month, and water sparely.


The April 9, 2019 meeting of the Capitol Hill Garden Club starts with refreshments at 6:45 pm at the NE Public Library, corner of Maryland Ave. & 7th St. NE. Meetings are free and open to all. Membership and Program Topic details: