Q. Our landscape is shaded by a large number of trees, so the lawn is not a tight sod. Right now, a grass of some kind is sprouting in the lawn area. Do you know what it is and have a recommendation as to how we should manage it?
A. I suspect that the plants germinating are one of the weedy grasses, rescue grass or annual bluegrass. It is relatively easy to prevent with a preemergent such as Crew, Dimension, or Amaze applied on or about Sept. 1. If you missed that opportunity the plants respond well to mowing. If you mow it at 3 inches, it produces an attractive lawn for most of the winter.
Q. We used whopper begonias for blooms and foliage in the summer shade garden. They still look great. I would normally replace them with cyclamen for the winter. What will happen if I just leave the begonias in place?
A. If the winter is exceptionally mild the begonias may survive and stay decorative through the winter, but the usual expectation will be for the begonias to freeze back with the first serious cold spell, probably sometime in mid-December. If there are cyclamen still available at the nursery in mid-December, you could plant them and expect them to last until May 1.
Q. What are the best conifers to consider for a living Christmas tree that I can plant in the landscape after it does duty as our decorated holiday tree?
A. I have had good response from both Deodar cedar and Arizona cypress as living Christmas trees. Sheared Aleppo pines and Italian stone pines also work well. There are some loblolly pines on the market, but they would only survive in the landscape if you had acid soil. For information on successfully using conifers for living Christmas trees, seek out some of the archived articles in plantanswers.com.
Q. Are slugs and snails a problem in the winter or are caterpillars still a threat? We have something eating our turnip foliage.
A. Slugs and snails are still a threat to primrose, pansies, spinach and other lush low-growing plants. Use slug and snail bait. Most greens including cabbage and broccoli will be under attack from cabbage loopers all winter. Use one of the Bt products such as Thuricide or Bio-Worm Killer to protect them. The usual problem with turnips is caused by flea beetles. Try a Spinosad product to control the flea beetles.
Q. Our local nursery has onion plants for sale now. Is it a good time to plant them? What is the best selection to use in our area?
A. If the weather stays cool, now would work for planting them, but to reduce the chance of onions going to seed, I like to wait until later in December. If your retail nursery is selling the mix of Dixondale onions, they are all good choices. I like the Legends selection for a mild yellow onion. For more potency, the Red Creole red onion is a good choice.