Time to focus on the summer heat. Here’s a to-do list for North Texas gardeners

We’ve had a few outbursts of warm weather, but cool spells have stepped to our rescue. For a while. But the calendar reminds us that the real deal is just a couple of weeks down the road. Gardeners need to focus on the warm months ahead. I have a checklist of things to get done.

Get the sprinkler system tuned up and ready. Be sure heads are functioning properly and aligned accurately. Clocks should be checked and adjusted to compensate for new plantings and other landscaping changes. Check that valves don’t leak when the system is off.

Plant only heat-tolerant annual color from this point on. No more geraniums, petunias or pinks. Opt instead for tropical annuals like caladiums, crotons, hibiscus, mandevilla, bougainvilleas, moss rose, purslane, angelonias, pentas, coleus, begonias, copper plants, purple fountaingrass and others.

Plant new turfgrass soon. Sure, you can still plant warm-season grasses well into August here, but it’s just easier now. Soils have warmed enough that the new grass will root quickly, yet air temperatures are still somewhat cooler so the grass will get by on only daily waterings during its first couple of weeks. This current four-week window is the best time of the entire year for getting new grass growing.

As a side note to that suggestion, if your St. Augustine never greened up this spring, that was probably freeze damage from the Christmas cold spell. It may have been mixed in with damage from chinch bugs from last summer that got confused with the drought.

If you’ve had an outbreak of purple nutsedge in your turf or even in landscape beds, you’ve arrived at the time to apply Image (the type for nutsedge control) or Sedgehammer. Read and follow label directions carefully for the best results.

Dichondra, poison ivy, bur clover or other late spring weeds can be controlled now with a broadleafed weedkiller spray. You’ll have the best results when these are applied to vigorous, active growth. Again, read and follow label directions precisely.

Early blight is likely to show up on tomato plants soon. Look for bright yellow blotches on lower leaves. Those blotches will then turn brown as the leaves shrivel and roll. Apply labeled fungicidal spray for control.

Don’t confuse early blight with spider mite damage which will begin to show up a few weeks from now. The mites will cause lower leaves to turn pale yellow or tan, then dried and brown as the damage flushes upward. You’ll be able to see the nearly microscopic mites if you thump a few leaves over a sheet of white paper. They will be the tiny specks that start to move about freely after a few seconds. Apply an insecticide labeled for control of mites.

Bagworms will be appearing on junipers, arborvitae, cypresses and other conifers in the next several weeks. At first, they will be very small and quite mobile as they begin feeding. They will make their protective bags from the plants’ needles, and they will pull them behind them. Spray while they are still mobile and you’ll get total control. Almost any organic or inorganic insecticide will work as long as they’re still feeding.

Crape myrtle bark scales are the unsightly white insects that may plaster the stems of these popular bloomers during the summer. They exude sticky honeydew, and that honeydew in turn gives rise to black, sooty mold. To prevent the mold, you must prevent the honeydew, and to do that you need to avoid the bark scale. Apply a soil drench of Imidacloprid systemic insecticide around the plants’ drip lines. It will be taken in through the roots to offer protection against the scale as well as crape myrtle aphids. That drench should be made as soon as possible now.

Canna leafrollers can also be prevented by a soil drench of Imidacloprid applied at this time. There are actually a couple of species of these nasty insect pests that construct their cocoons within the rolled leaves. If you prevent them you’ll have lovely tropical bloomers. If you don’t, you’ll have unsightly, terrible-looking plants that will be ready for composting.

Insect galls are commonplace. They’re strangely abnormal growths on the leaves and twigs of trees and shrubs that are usually the result of insect stings and subsequent laying of eggs. You’ve seen them, but you may not have known what they were. Woody oak galls and wooly oak galls are two common examples. So are the galls on the leaves of hackberries, cottonwoods and pecans (pecan phylloxera galls). The good news is that these galls are, for the most part, harmless. There is nothing you can do to prevent them and rarely anything you can do to cure them. Just ignore them. Your trees will be fine.

Chiggers are out there. If you go “out there,” too, they’ll climb aboard. If you’re new to chiggers, they’re the tiny pests that hang out in bermudagrass and weed patches from mid-May until it’s really hot in mid- or late summer. Their bites are tiny but ferocious and the itching will keep you awake nights. Theoretically you could spray an entire yard to control them, but I’ve always found it much easier just to put DEET insect repellent on my legs and feet, socks and pants before I go outside.

Your second application of pre-emergent herbicide granules is due now. If you made your first application back in early March, you’ll want to give your lawn its “booster shot” of Dimension, Halts or Balan granules the same relative time in June to prevent crabgrass and grassburs for the full growing season. If you missed the first treatment, there is no point in making this treatment.