Dear Neil: Two of our peach trees have dropped massive quantities of leaves. I’ve never seen this before. What could cause it?
A: This had to be a major attack of some sort. Either peach tree borers could have caused massive damage to the lower trunks of the trees, some type of herbicide might have been applied on one side of the trees, some kind of contaminant could have been left in a sprayer that was used to apply something to the trees — something of that sort. If this were a large shade tree I would have suspected a lightning strike. When I read your question and before I saw your photo I suspected peach leaf curl, but that’s certainly not the cause here. All I can do is guess.
Dear Neil: Our HOA is requiring that we modify floor plans for new construction. How close to beautiful native oaks can we pour the foundation?
A: Have a certified arborist come on-site to help you. It will depend on the type of oak, whether any fill will be added (that’s especially damaging) or any roots cut, also on the current health and vigor of the trees and whether the house will have one or two floors. Allow enough room for the growth of the trees’ trunks. Ideally you’ll be at least 8 or 10 feet away, but with care you could be closer.
Dear Neil: Several in our neighborhood have volunteers of this plant and we’re wondering whether we should save them.
A: No! This is Japanese privet, otherwise known as Japanese ligustrum. Although it’s an attractive large shrub to 20 feet tall and 15 feet wide, and although it produces fragrant (not entirely pleasant) white flowers that bees and butterflies love in spring and masses of purple fruit in the fall, it may be one of the two most invasive plants in Texas (the other being its sister, Amur River privet). It costs me hundreds of dollars each year to have these plants dug out of our 11-acre wooded acreage. Birds bring seed in from escaped plantings up and down the county roads around us. Don’t add to the problem in your town!
Dear Neil: What would dig these holes (see photo) in my St. Augustine in the middle of the night? What can I do to stop it?
A: Armadillos. I have a good discussion on trapping them in humane traps in the FAQ pages of neilsperry.com.
Dear Neil: We have several large, mature oaks that have lots of roots on the surface of the soil. Can we cover these with lawn dressing? Or at least partially cover them?
A: This is absolutely normal for many species of trees. That’s because 90 percent of any tree’s roots are in the top foot of soil. As the tree grows larger, so do its roots. They expand up and out of the soil. Unless there has been active erosion around the trunk, you don’t want to add soil. They’ll just continue to grow up and out of that soil, too. Your better solution would be to work up what soil is there and plant shrubs or a tall groundcover to conceal them.
Dear Neil: How do we encourage a mandevilla to climb a trellis we have in its pot? Only two of its seven stems are climbing.
A: You always think about how a vine climbs (by twining, by tendrils or by “holdfasts”). Mandevillas twine. Maybe you’ll have to coax a few of the stems to wrap around a nearby support, even tying them with plastic plant-tie if necessary. They’ll soon get the
Dear Neil: We’ve been in our house three years, but this live oak has been planted 10 years. It’s yellowed and stunted. What might be causing it, and what could we do to help get it going, or is it a lost cause?
A: I can see why you’re concerned. I’ll list a few things that might cause your tree to look this way. First, it might have been planted slightly too deeply. I can’t really see, but it looks like the root flare may be down in the ground. You want it to be right at, or slightly above the soil line so that the roots will expand up and out of the soil over time. Trees planted too deeply really never do recover. A certified arborist could use an air spade to open things up. Nitrogen might help, even to the point of having the arborist inject it into the vascular system of the tree. That would give you a quick idea of whether this was a nutritional issue. I’ve seen a few cases where severe woody oak gall infestations left trees looking this weak. I think you need an arborist.
Dear Neil: What is wrong with our grass? We pulled on it and it didn’t come loose easily, so we don’t think it’s take-all root rot. It’s spreading. What should we do?
A: The grass appears to be very dry, and it looks like it’s been that way for a long time. It almost looks like there is a thatch layer of undecomposed organic matter (grass clippings) through which the grass roots have a hard time growing and through which water and nutrients have a hard time passing. Take a square-bladed shovel and dig a small, three-sided flap to see if you find such a layer. It’s not nearly as common with St. Augustine as it is with bermuda. If you do find it, you’ll want to rake briskly to remove all the thatch before you replant. Or, it’s also possible that it’s old damage from chinch bugs left over from last year. The dead grass would still be there. You’re going to need to think back and do a bit of on-site research to help me figure out this answer.
Note to my readers: I’ve had a huge influx of questions while Texans have been at home. My replies will be shorter as I try to catch up. If I don’t answer your question it probably means someone else asked it here recently.
If you’d like Neil Sperry’s help with a plant question, drop him a note in care of The Eagle, P.O. Box 3000, Bryan, Texas 77805. Or email him at email@example.com.