Q: I discovered four saddleback caterpillars while deadheading my Knockout roses. I want them gone! Should I get rid of the roses? — Ellen Peterson, Sugar Hill
A: I have good news! Saddleback caterpillars rarely reinfest the plants where you find them. They are very sporadic in the landscape. I've found them on canna, iris, pear and redbud. Leave your roses alone and simply wear gloves and keep an eye out for the little green creatures on other plants while you work. Natural predators do a good job keeping their numbers in check. I have pictures of other common venomous caterpillars at bit.ly/venomcaterpillar.
Q: My neighbor was burning debris and the fire spread into my yard while I was away on vacation. My 30-foot-tall cedar tree is brown on one side. The top and one small side are still green. Is there anything I can do to save it? — Joni England, email
A: This is a situation where only time will give an answer to the problem. You'll just have to wait and see how much of the tree was truly affected by the heat. Sometimes, branches that look brown will sprout back out. There's no real danger in leaving the tree up for a while just to assess what happens. After one year, if branches seem dead and are falling from the tree, then you can remove them. The tree may be misshapen but still could live a long life.
Q: I have a ligustrum/lorepetalum hedge that is 20 feet tall; it has gotten unmanageable. I would like to take it down to 10 feet. Can this be accomplished at this time of year without killing them? — Loralee Rader, Canton
A: It won't kill them, but keep this in mind: A big consideration when pruning is how ambient temperatures will affect the plant's response. With hot temperatures, there's little stimulation for a shrub to recover and grow more foliage after you prune. In early spring, warming temperatures stimulate a plant to rapidly grow new leaves and cover over any cut you make. If you are in a situation where you are forced to prune at this time of year, you could do it, but you will look at bare stubs for much longer than if you did the pruning in early spring. Consider removing a quarter of the plant now and the rest in February.
Q: What do you think about Tenacity or Poa Constrictor to remove annual bluegrass from my lawn? — Patrick Kelley, email
A: Both products are used by professionals and both are available to homeowners, though they are expensive. That said, you have to be very careful to read and follow the label on each one. They can be used on some lawn grasses, but not others, and timing the application correctly is important. You have to be really careful with mixing. Remember that “annual” bluegrass is a misnomer. There are biotypes that behave more as a perennial plant and some are resistant to these and other products. There is no silver bullet.
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