Bid a fond farewell to damaged Chinese tallow
Q: I am trying to remove lawn grass from a part of my yard. There are three large, old crape myrtles in that area, and they have extensive root systems. In removing the grass, I have damaged their roots and now numerous sprouts are coming up all over the place. I don’t want to hurt other plants nearby (including the three mother crape myrtles). Is there anything such as Roundup that I can apply to the sprouts to kill them without harming the desirable plants?
A:
No, because they are parts of those mother plants. If you dig one of them up, you’ll see that it is tethered to the main tree. I’ve had the same issue a few times when I’ve planted shrubs near a crape myrtle, and I’ve found that using a sharpshooter spade to remove those tethering roots usually discourages additional sprouts after a short period of time.
Q: Our Chinese tallow tree was damaged badly by the cold of February 2021. We lost half the tree and had to have an arborist remove it. It developed a fungus on the trunk. This year the fungus diminished in size. Is the tree still at risk of dying?
A:
“Dying” is such a relative term. A gnarly tree can be technically alive but visually unattractive (as in “worthless”) in the landscape. At that point, it’s time to replace it. I can’t say that regarding your tallow tree because I can’t see all of it.
I personally like the tree a lot. It was the first tree I grew in my backyard nursery decades ago when I was in high school. Little did I know then, however, how invasive it is in wetlands
in South Texas.
I don’t think your tree is going to die anytime soon in your landscape. That is, unless we hit another really bad cold spell like we’ve had the past two winters. My suggestion, however: Take this opportunity to change to another more desirable species.
Q: Can you tell me what is happening to this boxwood? It is one of 15 in a hedge, and all the others are healthy and green.
A:
This plant looks like it got too dry back in the summer. Notice that the
browning is all happening from the tips of the leaves back toward their stem ends. Equate that to poor circulation in the human body when parts don’t get enough blood. Frostbite shows up at the tips of our fingers and toes, and in our earlobes. The leaf tips are the areas farthest from the roots, so they’re the first to dry out and the last to get water.
This one plant somehow missed one or more waterings. If you have an automatic system, check the head that serves it. If you use a hose-end sprinkler, vary where you place
it when you water the lawn. That way there will be less chance of missing this plant entirely. It looks like it will probably bounce back come spring. Apply an all-nitrogen plant food in early March and keep it watered at all times.
In case anyone suggests it might be the comparatively new boxwood blight disease that is common in the East and Midwest, this fact sheet has photos that show how the symptoms vary from those in your photo: https://apsjournals.apsnet.org/ DOI/10.1094/PHP-06-200053-DG.
Q: We are going to have foundation work done this winter. I know that’s the best time to transplant established shrubs, but I’m wondering if it’s worth the effort to dig and replant 25-year-old hollies, abelias and boxwoods?
A:
In my opinion, no. Replacement plants aren’t all that expensive compared to the cost of hiring two or three people to do all that work for you — or the backbreaking work of doing it yourself. Plus, if they’ve been growing in group plantings, you’ll never reassemble them so they’ll look right. Plus, if they’ve been pruned repeatedly, they’ve probably lost most of their vigor. And landscaping styles have changed a lot in those 25 years, as have your family’s needs.
My vote is that you enjoy redoing your landscape by starting with a new design and new ideas. Spend a little time over the winter laying out your goals.
Q: I have five Shumard red oaks. Why do some have better fall color than others? In fact, the “good” ones don’t even seem to be the same from one year to the next.
A:
That’s just the genetics of red oaks and fall color in general. It depends on rainfall in early fall, then enough dry weather in midautumn to stop new growth. It also centers on the exposure to cool weather to start the changeover of pigments within the leaves and vigor of the individual trees.
Oaks tend to vary a lot from one tree to the next in many respects. You’ll see it in the growth habits of live oaks. Some will have small leaves, others much larger. Some will have arching branches, others ascending. Red oaks’ colors will vary, but so will whether they hang onto their leaves all through the winter.
Q: I know I’m not supposed to cover the exposed roots of my magnolia tree with soil. I’ve going to plant English ivy, but I’d also like to use small river rocks over part of the root system in an area that has eroded. Will the rocks be of any harm?
A:
No, they do not compact to stop flow of air and water into and out of the soil. All will be well.