Q: Something is eating my collard plants. Little tiny caterpillars are making holes in the leaves. Kathy Mosher, email

A: You have cabbage worms. Despite their name, cabbage worms attack collards, cabbage, kale, Brussels sprouts and broccoli plants anytime you plant them in spring, summer or fall. Planting early or planting late doesn’t seem to make much difference. The best way to control them is to use an organic spray that contains Bacillus thuringiensis (abbreviated B.t.) on the leaves when you plant. Repeat every seven days.

Q: I would like to plant a crabapple tree in my yard. What varieties would be good for my area? I would like to use the fruit for jelly. Fran McLeod, White County

A: Fall is a great time to plant trees! If you are making jelly, you probably want a large-fruited crabapple. ‘Dolgo’ is attractive and commonly available. ‘Redflesh’ is crimson-colored throughout. Avoid ‘Hopa’: It is disease-prone and short-lived.

Q: We have battled voles for years in our big shrub/perennial garden and they love chewing the roots. For my new hydrangea, my husband suggested taking a large black plastic pot, cutting a ring 8 inches tall, and planting the new shrub through it. I would add expanded slate (Permatill) inside and outside the ring. Do you have any other suggestions? Susan Guillebeau, email

A: The plastic ring filled with Permatill is a great idea. Voles won’t be able to easily tunnel through the collapsing soil to the roots. My go-to vole response is to use multiple mousetraps (at least six) for control. My best bait is instant apple-cinnamon oatmeal. Mix a tablespoon of the cereal with just enough water to wet it until it is the consistency of thick cookie dough. Put this on the mousetrap trigger and a vole will have a delicious last meal. Be sure to cover each trap so birds can’t find it.

Q: Is it OK to use bagged grass clippings as ground cover/weed control? Rick Davis, Dunwoody

A: A lot depends on how many weed seeds are in the grass clippings. It also depends on where you use them. I would not use grass clippings in a vegetable garden because weed control is such a problem there in the best of circumstances. On the other hand, if you have a wooded area where you are just trying to keep the soil cool and moisture retentive, a few weed seeds in the clippings shouldn’t be a problem.

Listen to Walter Reeves’ segments at 6:35 a.m. on “Green and Growing with Ashley Frasca” Saturday mornings on 95.5 WSB. Visit his website, www.walterreeves.com, follow him on Twitter @walterreeves, on Pinterest, or join his Facebook Fan Page at bit.ly/georgiagardener for more garden tips.