September Gardening Checklist for Austin and Central Texas

September Gardening To-Dos

Okra - September Gardening To-Dos

Keep harvesting okra

The calendar says September is the beginning of the fall season, but the heat may not end until late in the month or October. The shorter days will trigger fall blooms for asters and other perennials. See below for things that should be on your September gardening to-dos.

Things to Do in the Garden for September


Fertilize roses and fall blooming perennials like asters and chrysanthemums.


Keep watering trees deeply and slowly until fall rains return. Stick with regular irrigation for all other plants.


Divide and transplant iris, cannas, daylillies, liriope, and amaryllis. Add perennials, herbs, and ornamental grasses later in the month, making sure to irrigate regularly until fall rains come. Plant spring flowering bulbs.


Start gathering fall leaves for the compost pile. Replenish mulch if needed.


Watch for brown patch as temperatures cool. Treat when daytime temperature drops below 85° F. Continue mowing and irrigation schedule.


Continue to monitor for fall webworms. Give those spider mites one last blast of water. Watch for caterpillars on brassica plants, then remove them or dust plants with Bt.


Deadhead flowers to encourage a last flush of petals. Prune reblooming roses this month if you haven’t already. Cut them back no more than 1/3. Shear hedges this month. Protect plants from antler-rubbing deer this month.


Expect growth to slow down a bit as the days grow shorter and milder. Add an extra week or two to your expected harvest date to account for what Travis County Master Gardener Patty Leander calls, “the fall factor.” Continue to grow your own transplants indoors under grow lights or outdoors under partial shade. Broccoli, cauliflower, cabbage, kale, mustard and other greens will be transplant size in just 4-6 weeks. Sow seeds at weekly intervals to keep a ready supply of baby plants on hand to tuck into the landscape, into a container, or to replace mature plants that are harvested for the kitchen. Gradually expose indoor transplants to outdoor conditions, then plant them in the vegetable beds the last two weeks of the month. Let your southern peas dry on the vine, then shell and store in a cool dry spot until ready to eat over the winter. Seed root crops in moist soil; thin to the proper spacing soon after they emerge. Plant cool-season flowering plants like snapdragons, dianthus, alyssum, pansies and nasturtium. These bloomers like cool growing conditions so don’t plant until later in the month. Plant sugar snap peas and snow peas during the last two weeks of September. See the full Vegetable Garden Planting Guide (Español, 繁体中文) and Vegetable Varieties for Central Texas,


Your September Indoor Gardening Checklist


This is the last month that you will fertilize your houseplants twice monthly, or as recommended by the plant label. .


Before bringing plants inside, consider leaching by pouring double the container size of water to wash excess salts out of the soil.

Daphne on CTG - September gardening to-dosAs a contributor to Central Texas Gardener (CTG), Daphne Richards, County Extension Agent-Horticulture, answers questions and shares knowledge on new and tried & true plants for Central Texas.  Check out some of our favorites for September!

CTGPecan Tree Aphids|Daphne Richards|Central Texas Gardener
CTGAnimals chewing tree bark|Daphne Richards|Central Texas Gardener
CTGWhat’s wrong with my Mandevilla plant|Daphne Richards|Central Texas Gardener
CTGWhy jalapenos turn red|Daphne Richards|Central Texas Gardener


Get Growing!

President Abraham Lincoln said “I want it said of me by those who knew me best, that I always plucked a thistle and planted a flower where I thought a flower would grow.” This handy reference will help you keep your garden free of weeds and serve as a reference for what things to do in the garden each month: January, February, March, April, May, June, July, August, September, October, November, and December.

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