The fall vegetable garden

County Agent’s Corner

A fall vegetable garden

A fall vegetable garden

Summer vegetables continue to be harvested and will until the first killing frost. When will that be? Your guess is as good as mine. Oct. 15 is the day I usually target for a frost event, but it seems that summers have been extending themselves the last few years.

Some years we have had a light frost or two in October, then continue to pick tomatoes and peppers into December. That is the exception rather than the rule. During frost events you may choose to cover your summer crops with a row cover or some other form of protection.

Several of our larger producers have high tunnels, similar to a greenhouse but without a heat source. The tunnels are opened on warmer days and closed on cold days and at night to trap the heat. This may extend their season well into late fall or early winter.

The good thing about living in Alabama is that we can grow some type of vegetable crop year round. The crucifer family, also known as brassicas, or cole crops, includes cool season crops such as broccoli, cauliflower, kale, Brussels sprouts and cabbage. You may also plant multiplying green onions, radish, beets, lettuce, carrots, and turnips as a fall crop.

These crops actually perform better in fall than spring due to the fact that we are progressing into cooler temperatures, rather than the heat of summer. As the temperatures approach upper 80s in late spring, these crops have a tendency to bolt, or flower, producing an off, or bitter flavor. This will not be the case in a fall planting.

August and September are the months to plant your fall garden. In a perfect world, I would have my soil prepared and my cabbage transplants ready to be planted the third week of August. It is often difficult to find transplants this time of year. I would expect to harvest just prior to Thanksgiving.

If you want to direct seed cole crops, seed would need to be planted around July 15. The issue with direct seeding is one hungry cricket can eat up tiny plants very quickly. Insects will also be an issue on transplants in August when insect populations are at their highest. A salad may look good to them, especially if it is dry and you are irrigating the planting. I can almost promise that if you are not regularly checking on your plantings, insects will eat them up before you know they are there.

These crops are also sensitive to calcium so make sure your soil pH is in the 5.8 to 6.5 range. They also require a touch of boron. If you haven’t used a fertilizer with micronutrients in a while, you may want to consider it. Fertilize the garden according to soil test recommendations and make sure you irrigate as needed. September and October are usually dry months.

Insects to be on the lookout for include the cabbage looper, imported cabbageworm, and the yellow margined leaf beetle. The cabbage looper is a small, skinny, green caterpillar that will arch its back when moving. The adults are night-flying brown moths that you are not going to notice. You may notice the frass (poop) they leave behind rather than the insect. You will definitely notice the holes they leave in your cabbage leaves.

The imported cabbageworm is a larger green caterpillar that does not arch its back as it moves. You may notice the cream-colored or white butterflies floating in and around your cole crops. These are the adults of the cabbageworm. Dipel, and other Bt products are effective in controlling these pests. It is an organic insecticide that should be reapplied as rainfall washes it off the plants. It must be eaten by the larva; it is not a contact material. It will not control the adults.

The yellow margined leaf beetle is a small beetle that will go after leafy crops such as turnip and mustard greens. You may find the adults and larva feeding on your crop. The Bt’s may be effective against the larva but not the adults. This pest is present in Blount County. If you’re going to grow greens, you may want to consider putting on preventative insecticide sprays to control this insect. They can destroy a green patch in a jiffy.

There is a good publication on planting fall gardens on the ACES (Alabama Cooperative Extension) website. Go to, click on publications and search ANR-1422 Basics of Fall Vegetable Gardening. Planting dates, spacing, and cold tolerance are listed in the publication. I will be glad to print them for you at the Extension office.

Get ready to put your vegetables and other items in the Blount County Fair. Individual exhibit registration will be on Sunday, Sept. 9, from 1 p.m. to 5 p.m., and on Monday, Sept. 10, from 8 a.m. to noon. There are youth and adult divisions for produce. Maybe you can take home a ribbon and some cash!

Dan Porch is County Extension Coordinator with the Blount County Extension Office. Dan lives in and loves Blount County and is available to answer your questions about conservation, agriculture, natural resources, and gardening. He can be reached at (205) 274-2129 or