Q. I planted two 12 foot Mexican white oaks in July this year. Can I prune some of the lower branches off the trunk now?
A. It is best for the tree’s growth rate if you do not reduce its leaf surface this early in its growth. Wait until the side branches grow to at least one inch in diameter before you do any pruning. If the tree was larger, January or February would be the best time to prune.
Q. We just moved into this home. It has wonderful trees but not much of a lawn until now. Suddenly there is a thick, attractive, grass-like plant growing. Is it ryegrass or some other kind of a weed? Should we attempt to control it with a herbicide? What is your advice?
A. I believe you are experiencing rescue grass. Some folks call it a weed and it can be prevented with a preemergent herbicide for grassy weeds (Amaze, Dimension) applied in early September. In my neighborhood, a number of us treat it as a winter lawn. Rescue grass prospers in shallow soil and shady sites during the winter. It is easy to mow and attractive over a long season.
Q. What do you recommend for winter color in the sun? Is there anything that survives in the shade?
A. Pansies, snapdragons, stocks, calendula, dianthus, and alyssum all do well in the sunny garden. Pansies tolerate the most cold. In the shade, cyclamen and primula are spectacular winter flowers. Cover cyclamen and primula if the forecast is for temps below 30 degrees F.
Q. Our office received a gift of phalaenopsis orchids last year. They were in bloom and beautiful for 3 months. Now the foliage is laying flat and they look dead. Will they perk up and ever bloom again?
A. They need to be watered each week by being placed in the sink to drain after the bark mix is wetted. Include soluble fertilizer in the water that is applied at least once per month. The fertilizer solution can be collected in a tray after it passes through the bark mix. You did not say anything about where the plant was placed? Phalaenopsis orchids seem to do well if they are placed in a window with a southern or eastern exposure.
Q. I have not had good luck with Bt protecting my broccoli and cabbage from cabbage loopers. Is there any other insecticide that works?
A. Sevin or malathion work. Make sure you follow the label instructions. They are different than those required for Bt. I am curious about the problem you had with Bt. Was the container more than two years old? Did you use a teaspoon of Dawn or a similar dish detergent to help the Bt adhere to the foliage? Is there a chance the damage was caused by beetles or snails rather than loopers? Did you spray the underside of the leaves? The caterpillars must eat the Bt as part of the foliage they are consuming. Bt is usually very effective in controlling cabbage loopers and other caterpillars.