GARDENER'S MAILBAG: Should I top dress my lawn?
Dear Neil: Is it a good idea to topdress a lawn with topsoil in the spring? My dad used to do that when I was a kid. I don’t see people doing it as much anymore.
I don’t mean to diminish your dad’s hard work, but it doesn’t make any sense unless you have a lawn that is uneven with ruts that need to be filled in. The problem with bringing topsoil in is that you run a big risk of introducing weeds like nutsedge at the same time. Plus, if you don’t really need to change the grade, you’re effectively raising your lawn each time that you add soil. You could change the flow of water across your yard. It wouldn’t happen in one year, but it could if you did it year after year. My vote is not to top dress your lawn.
Dear Neil: I have a tree that is leaning at about a 10-degree angle. It’s just far enough that it’s visually unattractive. I’ve only had the tree for three years. I wish I’d been more observant when it was planted. Is there anything I can do now to stake it or tie it to get it to grow straight?
If you were to do either of those things, as soon as you released it in a year or two (or longer), it would go right back into its old angle. The only way to correct the lean would be to dig and reset it. Since it’s only been there for three years, I would definitely recommend doing exactly that. Do so immediately, however, before it starts growing. And be sure you stake it and guy it to keep it perfectly plumb for the first 18 to 24 months.
Dear Neil: I have something growing on my crape myrtles. They still leaf out and bloom, but not as well as they should. Is this something I should treat or cut or both?
It looks like you’re about to have a full-blown infestation of ball moss (along with harmless lichens). This is a sister plant to Spanish moss. It is an epiphyte, meaning that it uses the host plant only for support, not for nourishment of any kind. The drop off in flowering is due to shading, and it will only get worse as the ball moss proliferates. You can use a copper-based fungicide to eliminate it, but read the Texas A&M application recommendations online before you do. Other than the shading, the plants do no harm to your crape myrtles.
Dear Neil: What can I use to kill wild onions in my lawn? I assume they’re not edible?
Use a broadleafed weedkiller spray (containing 2,4-D). I prefer to buy the concentrated type and apply it with a tank sprayer so that I can use a fine droplet size that will coat the leaves with the herbicide. I include one drop of liquid dishwashing detergent per gallon of spray to help the spray hang onto the waxy leaves. And, no, don’t eat any wild plants out of the onion family. Some of them are deadly poisonous. It’s absolutely not worth the risk. Let your favorite grocery store supply safe onion relatives for you.
Dear Neil: The townhouse we moved to two years ago has a bald cypress tree that is about 15 years old. It is planted 8 feet from a 4-foot-tall retaining wall that holds up the patio and house slab. Cypress knees have grown up 4 feet to the surface of the soil behind the wall. I’ve heard that they are not safe around foundations, and there is also a pond 25 feet from the wall. Should I remove this tree now before it causes trouble?
Cypress knees are incredibly strong. They can break concrete if they get wedged beneath it. The retaining wall scares, me especially since I cannot see it. I would suggest you have a Certified Arborist look at the tree to see if there is any way to manage the root growth in order to keep the knees from causing problems. I’m not a big fan of bald cypress trees in landscapes, and this is one of the main reasons.
Dear Neil: Attached is a pre-freeze photo of a neighbor’s persimmon tree. Do you have any idea what might have caused the unusual wounds?
Not with certainty. What an unusual photograph. One guess would be some type of a beetle with rasping mouthparts. It appears that this photo was taken during the growing season, since the plants have leaves. It also appears that the damage was new at that time. I would check the trunk now to see if it has healed. My guess is that it has. It’s also quite possible that a woodpecker has caused this. Their work, however, is usually shown by individual holes in rows, not continuous lines. Either way, I doubt if there is any damage done or any call to action.
Dear Neil: My wife bought the wrong tree about five years ago and now it has outgrown its space. Please tell us how to prune it to make it fit, or must we sacrifice it?
The best thing to do probably would be to remove some of the bottom branches and begin to train it as a tree with a visible trunk. In doing that you could also remove some of the branches that are beginning to extend toward your doors. I can see this as being a very pretty single-trunk tree in five or 10 years. We have an eastern redcedar that is visible just outside our living room windows. It’s now 30 feet tall with a trunk at least 1 foot in diameter, so it is easy for me to picture this Arizona cypress growing to similar dimensions.
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