Gardening This Weekend: July 7, 2016

• Tomato transplants. Last call for those of you north of and including Tyler to Waco to the northern half of the Hill Country. (It’s a very imprecise line, because we don’t know the date of the first killing freeze for the upcoming fall. Choose small and mid-sized varieties. Large types do not set fruit in Texas conditions. Planting at this time is required to allow enough time for fruit to mature. Call your nursery to be sure they have the transplants. Erect a lightweight shade for the first two or three days. South Texans, you have one or two more weeks, but don’t push your luck.
• New lawns. Water will be your key to survival. Water once or twice daily for the first couple of weeks – just 5 or 10 minutes per area. Don’t let it get soggy, but certainly don’t let the new grass get dry.
• Crape myrtles while they’re in bloom in nurseries to be sure you’re getting the exact shade that you want. Know the plants’ mature sizes before you buy them. Don’t plant large varieties in small spaces. Pruning to control size is not an option. It ruins their shape.

 

• Any unusual stem growth that ruins a plant’s natural shape and form. Some plants just get an urge to send out wild shoots.
• It is probably hot enough now to think about pruning oaks. Spring is off limits, due to risk of spreading oak wilt into the open wounds. Seal all wounds of oaks with a light coat of pruning paint. Wounds on other types of trees should not be sprayed with pruning paint (slows the healing).

 

• Most of your plants will benefit from feeding with an all-nitrogen plant food if it’s been more than 8 or 10 weeks since last you did. TAMU soil test results show that we almost never should add phosphorus (middle number of the analysis). Our soils are typically dangerously high in it, to the point of having adverse reactions to the plants. Water heavily after you fertilize.
• Apply an iron additive with sulfur included to correct iron deficiency of shrubs, vines and other fairly small plants. Keep iron off masonry and painted surfaces to prevent rusty stains. Sulfur helps keep the iron soluble for the plants. This is not a practical practice for large shade trees. Talk to your arborist.

 

• It’s prime time for chinch bugs in St. Augustine. They’re always in the hottest, driest parts of the lawn. The grass will turn wilted, then yellow (then dead and brown if you don’t act quickly). Part the grass with your fingers and look for BB-sized insects with irregular white diamonds on their wings, especially around the edges of the infested space. Spray with a turf insecticide immediately. Their damage can be very swift. They will return to those same spaces each summer about now.
• Gray leaf spot in St. Augustine. Look for angular gray-brown lesions, usually along the midribs of the blades, but sometimes also on the runners. This is caused by too much nitrogen in the hot weather. Discontinue all feedings of St. Augustine until September. For this outbreak, however, spray with a labeled turf fungicide. Your local independent retail garden center will be able to help you.
• Leafrollers on vinca groundcover, also in persimmons, chittamwood, redbuds, cannas, sweetgums and pyracanthas. Conventional sprays don’t do much good. Opt instead for systemics, but do so earlier in the summer, before the damage becomes evident.
• Lacebugs cause tan mottling of leaves of Texas sage, pyracantha, boxwood, bur oak, chinquapin oak, azaleas, fringeflower, sycamore and Boston ivy. You’ll see their black specks of excrement on the backs of their leaves. Systemics are the best means of preventing these, but apply them in late May or early June. Now about all you can do is to apply a topical insecticide to the tops and bottoms of the leaves.