You might think that gardeners would give the questions a rest in the middle of winter, but that’s not the case. Here are the ones that keep coming up year after year about now. (I’ve addressed one or two of these in recent weeks here. See if you remember them.)
Are poinsettias poisonous?
No. Research done at Ohio State in the 1970s found that the worst things that can happen are skin or eye irritation from the latex sap in their leaves and stems, also possibly upset stomach. But they’re not toxic to you or your pets.
What is the best living Christmas tree?
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Probably junipers, specifically, eastern red cedars. But they’re big and rather prickly. Or try something unusual like an Oakland, Willowleaf or Nellie R. Stevens holly trained into a pyramid. Pines don’t survive well in our North Texas climate. Neither do blue spruces or Alberta spruces, and Leyland and Arizona cypress are highly prone to diseases.
Should I keep leaves picked up off my lawn?
Yes. They harbor fungal diseases, especially with St. Augustine. Plus, the grasses remain green too far into the winter when they’re covered with a blanket of leaves. Then, if a strong wind blows the leaves away before a cold front, your grass becomes very vulnerable.
What plants can I set out now for a little color in the winter?
In terms of annuals, pansies and violas are the most cold-hardy. They can look like they’re absolutely gone in really cold weather, only to bounce back into bloom when they thaw. Pinks would come next, along with ornamental cabbage and kale. Dusty miller grows well alongside all of them. Snapdragons and sweet alyssum are close behind.
What grass can I plant now to cover bare soil? We don’t want mud tracked into the house.
Unfortunately, the soil is now too cool for grass roots to establish and grow. Ryegrass won’t germinate at these temperatures. St. Augustine would probably be killed out entirely, runners and all, if you were to plant new sod now. Bermuda sod might hold the soil and give you some type of covering for the next 10 or 12 weeks until you can plant a permanent grass, but that comment comes without guarantee.
When can I dig and move trees and shrubs to make room for new construction?
Now. Transplanting where digging is involved is a mid-winter task. The plants are dormant now, so there won’t be nearly as much shock to their systems. Hold the root balls together as you dig them, and replant them immediately at the same depths at which they were growing originally. Prune to compensate for roots that were left behind in the digging. Stay and guide the plants as needed to keep them erect.
When can I prune my shrubs? I have some that have become overgrown.
Evergreen and summer-flowering shrubs are pruned in the winter. Spring-flowering shrubs are pruned immediately after they finish blooming.
What is the best way to prune my crape myrtles back?
Just don’t “top” them. That is, don’t leave stubs. Put in other terms, don’t use pruning as a means of controlling height or width, because the plants are just going to grow back, and by then you likely will have ruined their natural growth form forever. It’s fine to remove an errant branch, but in doing so, make your cut flush with a remaining trunk. Don’t leave a stub. If you have a crape myrtle that’s too big for the space that you have for it, either move or remove it.
How do I prune my fruit trees, grapes and blackberries?
All of my other answers have been brief, so this one will be, too. Peaches and plums are pruned in winter to maintain their strong scaffold branching structure (three or four branches originating between 22 and 24 inches from the soil and trained to grow essentially horizontally). Remove vertical shoots. With apples, remove vertical branches (“watersprouts”). Little pruning is done to pears and figs. Remove 80-85 percent of the cane growth of grapes each winter. Maintain the vines on their wire supports. Wait to prune blackberries until after they finish bearing fruit. Canes that bore fruit are pruned back to the ground since they will never bear fruit again.
I see gray moss growing on the trunks and branches of my trees. Is that something that should concern me? What do I do about it?
Those are lichens. They’re a symbiotic growth of algae and fungi. As opposed to parasitic growths, that means that they’re harmless to the trees. They just start to grow there and eventually establish masses. If it makes you feel any better about them, they also develop on large boulders in nature. They’re no cause for concern.