GARDENER'S MAILBAG

Burls rarely kill limbs

By Neil Sperry | Published Wednesday, October 18, 2017

Share this page...

Dear Neil: I’ve had these “crop circles” in my lawn for the past four years. I’ve been told they’re caused by insufficient shade, lack of water, worms or fungus. Nothing I’ve tried has helped. What would you suggest?

If the problem has been ongoing for all of those four years it’s unlikely that it’s insects- or disease-related. Those problems tend to come and go seasonally. I do have to admit that the circular nature of the dead grass in your photo looks very much like brown patch fungus, but brown patch will show up only in the fall, once temperatures drop. The fact that it has persisted probably points to too much shade as the prime problem. It’s also possible that chinch bugs hit the turf and that it never had a chance to recover. It would have helped to have had a much higher resolution photo and more details about when the problem has been worst (summer or fall).

Dear Neil: Can you tell me what is happening to my mesquite tree? It has developed some large bulges that are forcing the bark outward. Does this threaten the life expectancy of the tree?

These are burls being formed. Burls are unusual growths that many types of trees produce for a variety of reasons. You’ll see them in oaks, and very large ones (automobile-sized) develop in redwoods in California. The grain of the wood within the burls is completely random. The wood can actually be very lovely. Burls are commonly used as veneers in the manufacture of fine furniture. However, most gardeners would prefer not to have burls develop in their prized trees. Affected trees can end up looking very odd. They rarely kill the limbs or the entire trees, but they aren’t attractive. If this is a prized tree you probably ought to have a certified arborist examine it to determine your best options.

Dear Neil: I have two mature Meyer lemon trees. I am concerned about the curled leaves on all their new growth (see photo). I’m not sure what to do with this.

This is citrus leaf miner. The larvae develop between the upper and lower leaf surfaces. You can see the tunnels they produce within the leaves in your photo. Control is difficult. The pests are most common on new, vigorous growth. Avoid removing the damaged growth as that will stimulate vulnerable new growth. Avoid nitrogen fertilizer at times when new growth is most vigorous (spring and early summer). Horticultural oils help if applied frequently. Spinosad also helps if applied once damage starts to become visible.

Dear Neil: Several months ago you discussed take all root rot on St. Augustine. You told that reader that they would need to resod the dead areas with plugs. Then, if TARR returned, that they should cover the grass with 1 inch of sphagnum peat moss. When should that be applied?

Take all root rot shows up from late March through mid-May, so that would be your time to apply the peat, but only if you see evidence of the fungus in the grass (yellowed blades, lethargic growth). There has been a lot of confusion about this disease since it first became widely noted 20 years ago. People mistake summer and fall problems such as gray leaf spot, chinch bugs and brown patch as take all root rot and apply peat in failed attempts to make things better. The acidic peat treatment only works on TARR.

Dear Neil: We missed fertilizing our azaleas in the spring. Is it too late to feed them this fall? What should our plan be for next spring?

Fertilize azaleas (and other spring-blooming shrubs and vines) immediately after they finish flowering in the spring by applying a high-nitrogen, lawn-type fertilizer with half or more of that nitrogen in slow-release form. I would probably not fertilize them this late in the growing season.

Dear Neil: I’ve attached eight photos of weeds in our buffalograss lawn. We’re starting to have bermuda invade it, and that’s OK, but these other weeds are taking over. What can I do to get a better looking lawn?

All of the weeds you photographed are broadleafed weeds, meaning they are not grasses. Apply a broadleafed weedkiller containing 2,4-D while they are growing actively to eliminate them. Do not mow for a few days before or after you spray, and use a tank sprayer with the nozzle set to a fairly fine droplet size. These materials do not act quickly, and you may have to treat a couple of times. Some of the weeds including the wild morning glory vine are warm-season weeds that are finishing up their growing seasons. You may not get the same good control of them now that you will next spring and early summer.

Dear Neil: My daughter lives in a part of the state where Gold Star esperanza freezes to the ground. Some years it comes back, but some years she has to replant. If she wanted to try covering it with mulch, when should she apply it and should she cut the top growth back first? If so, when? What kind of mulch should she use?

When I’m trying to protect tender sub-tropical plants, I cut them back the day after the first killing frost kills all of their top growth. I leave a few inches of stem, and then I cover them with shredded tree leaves, finely ground pine bark mulch or well-rotted compost. If there is danger of the mulch washing or blowing away I’ll put a piece of burlap in place over it and secure it with stakes at its corners.

Have a question you’d like Neil to consider? Mail it to him in care of the Wise County Messenger, P.O. Box 149, Decatur, TX 76234 or email him at mailbag@sperrygardens.com. Neil regrets that he cannot reply to questions individually.

Leave a Reply. Note: As of March 24, 2011, all posted comments will include the users full name.

WCMessenger.com News and Blog Comment Guidelines

You must be logged in to post a comment.