GARDENER'S MAILBAG: Will there be long term effects from the cold?
Dear Neil: I have two live oak trees that held onto their brown leaves much longer than the other live oaks in our neighborhood. I believe they are finally starting to grow, but I wonder if the damage from this winter is going to have long-term effects on them.
I have talked to several highly respected arborists and foresters and the consensus opinion is that, because live oaks vary so much genetically, that their reactions to the freeze of February will also vary. They say that we’re really not going to know for sure until later this spring and into the summer whether individual trees have been hurt. Look for pieces of bark to separate and fall in the process as the trees work to heal themselves. Hopefully, since you sent your question, your trees have started to catch up.
Dear Neil: Is it safe to use plastic bottles in the bottoms of my plant containers so that I won’t have to use as much potting soil?
Perhaps, but I’m not going to sign a blank check. It will depend on several factors. If you’re dealing with very tall pots (36 inches tall or taller), and if you will not be using any woody plants such as trees or shrubs that would be in them permanently, I guess you could do that. However, you might consider simply getting some lower-quality garden soil from a part of your vegetable or flower garden and putting that at the bottom. That would give your plants true soil in which to send their deep roots, but it would also lower the costs. You always want to use the highest quality potting soil possible for smaller pots and for the top surfaces of these large containers.
Dear Neil: I have two holly bushes in my front flowerbed. They have grown to the roof of the house and they have gotten too wide as well. They have lost many of their leaves due to the freeze. Would this be a good time to trim them back by about half?
If they haven’t grown back already, yes, you could do that. Some of our holly varieties did lose a lot of leaves after the cold and they’ve been slower to leaf out again this spring. Trim yours selectively, one branch at a time, to reshape and groom them.
Dear Neil: I have dwarf nandinas that have grown very unevenly. I admit I’m just getting around to sending my photo to you in April, but it makes it easier to see the disparity in their heights. What can I do to correct it?
It works for me! I use a lot of Compacta nandina. That’s the second-tallest variety, growing up to about 42 inches, although I keep mine trimmed at 24 to 30 inches by removing the tallest half of my canes completely to the ground every winter. That means that half are cut one year and have to send up new shoots from ground level one spring, and the other half gets the same treatment the next spring. All that works great for me 24 years out of 25. And then there is 2021. Because my nandinas lost almost all of their foliage, I cut the canes back to within 1 inch of the soil – all of them. Every last cane. The ground was suddenly bare. Now they are regrowing and filling back in at even heights. And the other thing you need to do to get a more uniform look is to plant your nandinas much more closely together. Perhaps at half the spacing you’ve used. Feed them with an all-nitrogen lawn food (no weedkiller included), and keep them damp at all times. They will take it from there.
Dear Neil: We have property in Central Texas. Over the past several years we have lost several post oak trees. What trees would you suggest to replace them?
I would use native trees so they blend into the surroundings visually. Of all of our native oaks, post oaks have some of the shortest life expectancies, so it’s not uncommon to have to replace them. That’s especially true when we build our houses and driveways around them. I’ve always thought that bur oaks were good substitutes. Their leaves are similar, but the bur oaks are far more adaptable and much longer-lasting. You could also use Shumard red oaks, Chinquapin oaks, even live oaks, cedar elms or pecans. Eastern redcedar junipers are often found growing with post oaks, so if you want an evergreen tree for privacy, it’s a great one that grows in a wide variety of Texas soils.
Dear Neil: Is it possible that this winter’s cold might have killed clumps of pampasgrass entirely? We have two plantings that don’t have even one shoot coming up.
The farther north you go in Texas this spring, the more commonly you see that happening. Pampasgrass was really leveled by the cold. Many who liked it and were growing it are going to have to replant it. And even where it is coming back, it’s doing so sporadically. Only portions of previously big clumps are sprouting up.
Dear friends… If you have written to me recently about a specific type of plant that is not leafing out, and if you have not seen a reply, it’s probably because someone else asked about it in a prior week. I’ve had scores of questions, for example, about xylosmas, citrus and sago palms in South Texas and oleanders, pittosporums, palms, Indian hawthorns and waxleaf ligustrums across much of the state. I prefer not to go over the same plants repeatedly here in my column. If you have recent copies of my column, please refer back to them. If you’re waiting to see if you’re going to get significant resprouting out of any of those plants, however, I can tell you that only the oleanders, sago palms and some types of regular palms are likely to do so. Each of those will require warmer weather, so continue on with your patience. We’re all learning on this one together.
Have a question you’d like Neil to consider? Mail it to him in care of this newspaper or e-mail him at email@example.com. Neil regrets that he cannot reply to questions individually.