August Gardening Checklist for Central Texas


The dog days of summer bring some of the biggest challenges to Central Texas gardeners. August is reliably hot and dry. Watering lawns and gardens becomes routine but even then, some plants succumb to the extreme weather. This month is a bit of a reality check for central Texas gardeners. I call it the “remove your rose-colored glasses season” to see what can actually grow and survive in your garden.

The good news is there are many landscapes plants that not only tolerate hot, dry weather, they are made for it. And there are even more plants being developed that withstand heat extremes. Keep in mind that well established plants tend to tolerate hot temperatures better than newly planted ones. So, evaluate your garden, identify what isn’t doing well and what is thriving, then plan to make adjustments. 

Here are some checklist items to be aware of and to do in gardens this month. Also, some things to do to help plants make it through climate challenges. 

What can be planted in August?

We all appreciate a little color in the August garden. If you can find them, replace exhausted annuals with transplants of heat tolerant annuals like marigolds, pentas, sweet potato vine or celosia. And if needed, refresh patio or porch containers with annuals.  

Turfgrass can be planted but get this done early in the month so that it has time to develop enough roots to carry it through the winter before going dormant. 

Plant fall flowering bulbs if you can find them. Bulbs suited to central Texas that reliably perennialize are Lycoris radiata – spider lily – and Rhodophiala bifida – oxblood lily. This is the best, no bending over, bulb planter.

Order seeds of wildflowers and cool season annuals as well as spring blooming bulbs for fall planting. If you are considering planting a tree, wait until at least October in central Texas. In the meantime, give thought to what tree, mature size and locate a source to purchase. Wait until weather cools to plant herbaceous perennials, shrubs and groundcovers.

What perennials are proven to be heat tolerant in central Texas? See my July gardening checklist for some of the plants that not only survive but thrive in Texas heat. Then, make plans to add them to your landscape in the fall which is the absolute best time to plant them in central Texas.

What to do in the Vegetable Garden in August

August is one of the most important months to make preparations to grow vegetables. Because, there is much that can be planted in September and October – more than 20 edible crops in central Texas. In warm climates, September through February is the easy gardening season. Weather is mild, pests are few, vegetables thrive in cooler weather and it is more comfortable to be outdoors. If you’ve been wanting to start home gardening, this is the best season to start.  

Prepare vegetable gardens for the cool growing season. August vegetable gardening to do list is clean the garden, remove weeds and debris from planting areas. Add compost or shredded leaves to enrich the soil. Order seeds for planting – beets, carrots, chard, lettuce, mustard greens, snow and snap peas, radish spinach and turnips.  Broccoli, cauliflower, cabbage and spinach can be started indoors in early August to grow transplants for fall planting. To have the best selection of varieties, order garlic for fall planting.

As far as actual vegetable planting in August, the list is short. Planting periods for vegetables by seed and *transplant for zone 8b central Texas are: 

Week 1 – snap beans, cucumbers, *eggplant, *peppers, summer squash, summer greens – Malabar/amaranth

Week 2 – snap beans, cucumbers, potatoes, summer squash, summer greens – Malabar/amaranth  

Week 3 – snap beans, cucumber, potatoes, summer squash, summer greens – Malabar/amaranth

Week 4 – artichoke/dormant crowns, snap beans, potatoes, summer squash

Pruning and mowing in August

Herbaceous perennials like salvia or lantana can be pruned by a fourth or one third to prepare for fall blooms. Shape summer annuals – angelonia, sweet potato vine, coleus, basil and others to keep them compact and full. Lightly shear shrubs such as boxwood or dwarf yaupon if needed. 

Roses lag in the heat of summer but reblooming types need attention in August to have nice fall blooms. Prune back by one quarter and remove dead or dried canes. Fertilize with a high nitrogen product, water thoroughly then mulch roses. This Organic All Purpose fertilizer for roses is an excellent option.

Lawn care in August

Mow lawns regularly, removing no more than one third of the leaf blade at each mowing. If watered, lawns still grow fast in August. Watering lawns and landscapes is critical in August in central Texas. 

How often, when and how much to water lawns? The answer is “it depends” on the type sprinkler, turf species and other factors. But the goal is to get soil moist down to 3 to 4 inches. A cycle and soak rotation helps accomplish this but requires monitoring. Most turf experts agree on twice a week watering or every 3 to 4 days in warm climates.   

Monitor the effectiveness of watering systems and adjust the schedule as needed. Avoid overwatering your lawn. Watering 3 to 4 times a week results in wasteful runoff, grows shallow rooted turf, may promote disease and can literally drown some plants. Observe sprinkler heads to ensure they are operating and covering properly.

Four water conserving strategies

  1. Mulch is one of the least expensive but most beneficial things to retain soil moisture. It protects plants during summer heat to slow down evaporation. Cover soil with 2 to 3 inches of mulch. This insulates the soil, lowering the temperature to keep plant roots cooler and helps reduce weeds.
  2. Rather than water the entire landscape, spot check for dry areas. Particularly shrubs and less established plants. Check soil moisture at 3 to 4 inches deep with your finger. If dry water just those plants with the hose.  
  3. Observe turf for dry spots. These are usually in full sun and yellowing while most other parts of the lawn are still green. Use your finger to check soil moisture and if dry, use a hose end sprinkler to water, rather than watering the entire yard.
  4. Heat and drought stresses trees. Check soil moisture and if extremely dry or trees are wilted in the mornings, water at the dripline with either a hose end sprinkler, bubbler or let a hose run. Move it periodically around the dripline to soak the soil. 

When is the best time to water landscapes? 

The best time of day to water lawns, shrubs and flower beds is early in the morning. If possible, set automatic irrigation systems to run between 4am to 9am. Use timers made for hose end sprinkler applications. For hose end watering the most efficient sprinkler is the impulse type, rather than oscillating. Here is my favorite watering wand.

If you have fruit trees like peaches or figs continue watering to have healthy foliage to energize trees for next year’s production.

What to fertilize in August

Fertilize roses after pruning with nitrogen. Also, patio pots and hanging baskets with water soluble nitrogen every 2 weeks. Should you fertilize turfgrass in August? No in central Texas wait until early September to fertilize lawns. 

Landscape pests in August

Hot, dry weather stresses plants, making them more susceptible to insect pests. Look for lacebugs if leaves are turning beige, have a mottled appearance and the underside has tiny black specks. Infested annuals may be removed and perennials can be cut back. Lacebugs must be managed quickly to prevent damage. A systemic insecticide as a preventive measure could be applied. 

Chinchbugs is a common lawn pest in hot and dry August. If turf turns brown in areas of full sun and it does not respond to watering, look for chinch bugs. At the edge of the brown area, inspect closely at the base of the leaf blades for small, black and white insects. If you find chinch bugs, apply a labeled insecticide appropriately. This pest can do serious damage to summer turf. 

Red spider mites are another hot weather pest. Their damage is similar to lacebugs but has delicate, fine webbing. Mites are hard to see, so hold a white paper under a leaf, thump it and look for tiny red specks. A strong blast of water to the underside of foliage may help, but application of a miticide may be needed if the infestation is severe. 

Armyworms can infest Bermuda grass in hot, dry periods. Be watchful because they move fast and turf will brown quickly. If you observe them, take control measures quickly. 

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