What to Plant in August in Southeast Texas (Zone 9)

Written By David Pool

If you're new to gardening, August might seem like the worst possible time to plant anything. It's hot, humid, and just walking outside feels like work.

But here's the good news—August isn't the end of the gardening season. In fact, it's the beginning of one of the best growing seasons we have here in Southeast Texas.

Our fall gardens often outperform our spring gardens because the soil is warm, plants establish quickly, and many pests begin to slow down as temperatures gradually cool. The trick is knowing what to plant now and what should wait just a little longer.

Let's take a look.

Start Planning Your Fall Garden

One of the biggest mistakes gardeners make is waiting until the weather feels like fall before planting. By then, you've already missed valuable growing time.

Many cool-season vegetables actually need to be started while it's still hot outside, so they'll be mature when cooler temperatures arrive.

If you don't already have a plan, now is the time to sketch out your beds, refresh your soil, and decide what you want to grow.

Vegetables You Can Plant Now

Don't Forget Your Second Round of Tomatoes and Peppers

This is probably the crop everyone gets most excited about—and for good reason.

One of the biggest advantages we have here in Southeast Texas is that we can grow two tomato and pepper seasons each year.

If your spring tomatoes are looking tired, covered in disease, or have simply stopped producing, don't be afraid to pull them out and start fresh. Young plants often outperform old, stressed plants once fall arrives.

August is the perfect time to start seeds indoors under lights or in a bright location, where you can control moisture and help them get established. If you don't want to start from seed, keep an eye out for healthy transplants toward the end of the month and into early September.

Some of my favorite fall tomatoes include:

  • Celebrity

  • Better Boy

  • San Marzano

  • Rapunzel

  • Sun Gold

  • Sweet 100

For peppers, almost any variety will work well for a fall crop, including:

  • Jalapeños

  • Serranos

  • Banana peppers

  • Bell peppers

  • Poblano

  • Cayenne

  • Habanero

  • Ghost peppers

The key is giving them enough time to mature before cooler weather arrives. Our warm fall temperatures usually provide plenty of growing time, and because nights begin cooling down, fruit set often improves compared to the peak of summer.

In many years, my fall tomatoes end up producing some of the best fruit of the entire season.

Southern Peas

Black-eyed peas, purple hull peas, zipper cream peas, and crowder peas all love the heat. August is still a great time to get another crop growing before cooler weather arrives.

Okra

If your current plants are slowing down, there's still time to start another planting. Young okra plants often produce well into the fall.


Bush Beans

Bush beans germinate quickly in warm soil and can produce a harvest before our first frost. Keep the soil consistently moist during germination.


Cucumbers

A late planting of cucumbers can provide a surprisingly productive fall harvest. Choose varieties with shorter days to maturity whenever possible.


Summer Squash & Zucchini

Many gardeners give up after squash vine borers destroy their spring crop. The good news is that late summer plantings often have fewer insect problems and can produce an excellent fall harvest.


Pumpkins (Early August)

If you're hoping for pumpkins by Halloween, now is the time. Choose smaller or shorter-season varieties if you're planting later in the month.


Start Seeds Indoors

Some of your favorite cool-season crops can be started indoors this month where temperatures are easier to manage.

Consider starting:

  • Broccoli

  • Cabbage

  • Cauliflower

  • Brussels sprouts

  • Kale

  • Collards

Growing them inside allows you to transplant sturdy young plants once outdoor conditions begin improving.

Wait Just a Little Longer

As exciting as it is to get everything planted, a little patience pays off.

Toward the end of August and into September, you'll be able to begin planting:

  • Carrots

  • Beets

  • Turnips

  • Radishes

  • Swiss chard

  • Lettuce

  • Spinach

  • Mustard greens

  • Arugula

These crops generally perform much better once nighttime temperatures begin coming down.

Herbs That Love This Time of Year

August is also a great opportunity to establish herbs that will carry you well into fall.

Good choices include:

  • Basil

  • Dill

  • Cilantro (late August into September)

  • Parsley

  • Chives

  • Oregano

  • Thyme

Many herbs actually become more flavorful as temperatures begin cooling.

Don't Forget the Flowers

Pollinators still need food this time of year, and adding flowers to your garden helps support bees, butterflies, and beneficial insects.

Consider planting:

  • Zinnias

  • Marigolds

  • Sunflowers

  • Pentas

  • Salvia

  • Angelonia

  • Celosia

Not only do they attract pollinators, but they also keep your garden looking colorful while your fall vegetables are getting established.

Give Your Soil a Boost

If you've been gardening all summer, your soil has worked hard.

Before planting, consider adding:

  • Compost

  • Earthworm castings

  • Quality organic matter

  • A balanced slow-release fertilizer like Microlife 6-2-4 Multi-Purpose

Healthy soil holds moisture better, supports beneficial microbes, and gives young plants a much better start.

Water Smart

August heat can dry out young seedlings quickly.

A few tips:

  • Water early in the morning whenever possible.

  • Water deeply instead of lightly.

  • Mulch around plants to conserve moisture and reduce soil temperatures.

  • Avoid watering during the hottest part of the day when much of the moisture is lost to evaporation.

Consistency is much more important than overwatering.

Don't Be Discouraged by the Heat

Every year I hear people say they'll just wait until fall because it's too hot to garden.

The truth is, this is exactly when experienced gardeners are getting ready.

They're starting seeds.

They're improving their soil.

They're planning their beds.

They're getting ahead so they'll be harvesting while everyone else is just getting started.

Gardening in Southeast Texas isn't about following a calendar from somewhere else. It's about learning our seasons and working with them instead of against them.

August may be hot, but it's also full of opportunity.

Get outside early, stay hydrated, and plant something. Your future self will thank you when those first cool mornings arrive and your garden is already thriving.

Happy gardening!

David Pool