When it comes to your lawn, this is a critical time in the growing season. Here are some guidelines.

• New lawns can be planted, but do so as quickly as possible. Sod offers the best and quickest method, but it's also the most expensive. Your goal is to have warm-season turf established and growing before the soil begins to cool drastically.

• Chinch bugs and gray leaf spot will still be active in St. Augustine while it's warm. Brown patch will show up as temperatures fall.

• Water in early mornings. That's especially critical with St. Augustine turf that will be vulnerable to brown patch fungus. Night watering will leave the grass wet, allowing quick spread of the disease.

• Apply a pre-emergent weedkiller in September to stop germination of cool-season weeds. It's far easier to prevent them than it will be to cure them. Apply Betasan, Dimension, Team or Balan for winter grassy weeds and Gallery for broadleafed weeds. Do not apply pre-emergent herbicides if you intend to overseed your lawn.

• Keep mowing your lawn at the recommended height right up to frost. Use your bagger to catch shredded tree leaves. Put them in the compost pile or use them as a loose mulch around shrubs and in the perennial garden.

• If you intend to overseed your lawn, do so in September. "Perennial" rye works best. It establishes most uniformly, plus it's much easier to maintain. The little difference in cost compared to annual rye seed will quickly be offset by the fewer mowings you'll have to give it. Neither grass will be perennial in Texas conditions.