Oh, the questions I am asked! There seem to be scores of them. I’ve boiled them down to a precious few, and these are the ones that fall from the most people’s lips.
“Will this winter’s cold reduce the summer populations of mosquitoes and other insects?”
Not at all. Insects are hearty souls, well prepared to withstand much colder winters than we’ve had here in North Texas. Ask the folks in Minnesota and even farther north about their condor-sized mosquitoes. Nope — be prepared, just like you always are. The insects will be back, and they’ll be twice as hungry.
“When should I apply my pre-emergent weedkiller? I see weeds already.”
Careful! Remember that pre-emergent weedkillers are applied before weeds actually germinate (“emerge”). Once you can see them it’s too late for pre-emergent products to work. If what you’re seeing are grasses, you’ll have to wait until late August or very early September to apply pre-emergent granules to stop the next generation. There is nothing you can apply once they’re up and growing. On the other hand, broadleafed weedkiller sprays containing 2,4-D will eliminate henbit, clover, dandelions and other non-grassy weeds. The next pre-emergent applications come in the first two weeks of March and they are intended to stop the growth of crabgrass and grassburs.
“How can I tell if a shrub is actually frozen or if it will come back? I’m referring to oleanders and gardenias.”
If stem tissue is shriveled and brown, it will not come back from its stems and that tissue can be trimmed out immediately, even if it means cutting the plants completely back to the ground. You happened to choose one plant from each category. Oleanders will almost always come back strongly from their root systems. Gardenias that are frozen do not. They are considered as being lost to the cold.
“How long do I have to wait before I can plant roses again if I had rose rosette virus?”
You hear all kinds of answers to this question. As far as how long it would remain in the soil, if you removed all the roots as you were discarding the plants, you probably wouldn’t have to wait more than six or 12 months. However, if there is rose rosette virus still active within your neighborhood, it will probably spread right back onto your new plants via the microscopic mites that serve as its vector. Since we have no means of controlling those mites, it’s hard for me to recommend replanting roses until a better work-around has been found.
“When am I supposed to prune my oak trees?”
This is driven by the oak wilt fungus that is so devastating to mature live oaks, red oaks and many other oaks as well. It is spread from the fungal mats that form inside the bark of infected trees, and those mats are active in the spring. Arborists and plant pathologists tell us the best times to prune oaks will be between mid-July and early February. Spring is the time to avoid. Be sure your pruning tools are clean before you start every cut, and seal all cut surfaces with pruning paint to prevent entry of the fungus.
“How much can I prune my shrubs back, and when should I do it?”
That really depends a lot on the types of shrubs. Most types, however, can be trimmed by 25 percent to 35 percent in both height and width. However, you don’t want to do that repeatedly. If you have plants that are consistently growing too tall or wide, perhaps you should think about replacing them with something a bit smaller. Use lopping shears and hand tools to avoid the squared or rounded look. Remove dead wood first, then any erratic growth that detracts from the natural form of the plants. All of this pruning should be done now, before new growth begins for the spring. The exception would be with spring-flowering shrubs. With those you want to wait until immediately after they finish blooming.
“Why are my boxwoods golden-brown and my Indian hawthorns purple?”
That is all a response to the extreme cold of this past winter. The yellow and red pigments become stronger and overwhelm the green shades in their leaves. The good news is that all of these will return to their normal lush colors come spring. These old leaves will be shed anyway, so don’t worry about trying to trim to remove them.
“Why do I see people topping their crape myrtles?”
OK. I’ll admit it. I’m the one asking that question. I ask it because I have absolutely no answer. It’s a horrible thing to do to any plant, and why crape myrtles get singled out for that barbaric abuse is way beyond my understanding. It ruins their shape. It delays their first round of blooms (often by six to eight weeks). It causes their flower heads to be huge and heavy so they flop over from their weight. And in the winter the plants are simply ugly. So to that question I give an answer I try to use as seldom as possible: “I have no idea.”