Q. At this time of year, I usually cut a few branches from some of my flowering trees and shrubs to force indoors. I never have any luck with lilac. Why is that?
–Jennifer Berryman, Chicago
A. The later in the season a shrub normally blooms, the longer you want to wait before pruning its branches for forcing. Lilac blooms in early to mid-May — later than many shrubs typically forced, such as magnolia, forsythia, redbud, witch hazel and flowering quince.
You should wait until late March or even early April before selecting lilac branches with fat flower buds to force indoors. To aid in water uptake, be sure to peel and slit the bottom few inches of the branch or pound it with a hammer to soften the tissue. Recut the butt end once a week and keep submerged at all times.
Q. We have a large 3-by-4-foot Christmas cactus that blooms beautifully each year. About 15 percent of the plant has wilted shoots (although sometimes they produce flowers).
–Dick Heinrich, Michigan City, Ind.
A. It sounds like your plant might need repotting. Most Christmas cactus should be repotted every two to three years. Although they prefer slightly potbound conditions, an overly dense plant can interfere with good drainage.
Spring is a good time to repot most houseplants (or whenever it has finished flowering). Replant into a clay pot one size larger than your present size. Use a commercial succulent potting mix or make your own from equal parts shredded peat moss, sterile houseplant potting mix and sand. Check for any rotten roots or diseased tissue at this time and prune out problem areas using sterile pruners.
Q. I leave all my ornamental grasses standing over winter and then prune them hard to the ground in early March. Should sedges be treated in the same way?
–Frank Borman, Berwyn
A. Many sedges in our hardiness zone are evergreen and do not dry out in winter the way ornamental grasses do. Therefore, it’s not necessary to prune them to the ground. After a particularly harsh winter, they may look a bit tattered and the foliage may have browned. You can either trim out the unattractive foliage or cut the entire clump to the ground. This is a good time to dig and divide sedges and grasses.
———-
E-mail: home&garden@tribune.com.
