Q: I know you have told in your column when to prune crape myrtles, but I lost the article. When is the best time to prune crape myrtles?

A: The time to prune a crape myrtle is approaching — late February and early March.

Q: When should I sow zinnia seed? I want the flowers to grow as early as possible.
A: Zinnias love hot weather. Therefore, zinnia seeds will not propagate until the weather is consistently warm. Wait until May to plant them.

Q: I have a plant that my mother calls a mother-in-law’s tongue. Can you tell me its proper name? How do I go about separating the plant? The pot is so full the sides have split open.
A: The plant’s botanical name is Sansevieria trifasciata. In this area, “snake plant” is another common name for the plant that thrives when its roots are crowded. Instead of separating the plant, transfer the entire clump to a container one size larger. Add additional nutritious, textured soil and water well. Place the container in indirect sunlight and do not add additional water until the soil feels dry.

Q: The purple salvia I planted last summer died. Where should I plant salvia, in sun or shade?
A: Salvia thrives in full to partial sun, in rich nutritious soil, in a planting hole the depth of the root ball and twice as wide. Maintain a watering schedule until the plant becomes well established. Apply a layer of mulch to help retain water, to keep the root system cool and to prevent weeds from propagating in the planting bed.

Q: The Knockout roses I planted last year have grown really tall and bushy. When and how should I prune them?
A: Prune your roses in late February or early March, as soon as new growth appears. Using sharp pruning clippers, make slanted cuts about a quarter-inch above a growth bud. Prune conservatively, leaving as much strong healthy wood as possible because nutrients are stored in the woody canes. Large, healthy wood promotes flowers. Begin by removing all damaged, diseased or dead wood. Remove small spindly wood. Remove wood in the center of the plant and in instances where one limb crosses over or rubs against another limb, remove the less viable of the two limbs.

Q: I want to buy a couple of matching shrubs and place one on each side of my front steps. Can you recommend a shrub that would look good beside my front steps?
A: The shape and style of your home makes a difference in the type of shrub that would enhance the front entrance. Does your home have a narrow stoop or a wide front porch? Is your home a cottage, a ranch or a Southern-style home with a wrap-around porch? Are there 10 steps or two leading to the front door? All of these elements make a difference in the type of shrub to select. Email me again and provide more information, or attach a photo and I will make a recommendation.