You can create a fall vegetable garden in Oklahoma and much of the South, but you should start when the weather is still warm. August and September are the best months to plant seeds and starter plants. Still, there’s a conundrum. Even in September, Oklahoma’s weather can be exceptionally warm, and some cold-weather vegetable favorites don’t want to start when temperatures are above 85F. Still, there are tricks you can use to make the vegetables think your weather is cooler.
Some vegetables like lettuce, kale, spinach, parsnips, rutabagas, beets and turnips don’t like warm weather. You can start leafy greens indoors under lights, but I often forget this step because I’m working so hard in the rest of the garden. So, here’s a trick I use to fool cool season vegetables into sprouting despite the weather. I place shredded leaves or homemade compost three inches thick and create a trench to sow the seeds. I water down this trench the day before I want to sow. It helps cool off the soil and makes it damp especially if you use shredded leaves. The leaves hold in moisture and make the soil ready for your seeds. Sow seeds at twice the depth of their size in the trench and don’t fill the trench all the way. Keep that area watered everyday, even twice a day if you have drying winds. Soon, you’ll see germination. As the seeds grow, thin plants giving them space to grow. Read seed packets for spacing requirements. Root crops like turnips, carrots and beets need more space to form than lettuce and other greens which can be grown to full size or grown as microgreens.
The most difficult thing about growing a fall garden in a warm climate is keeping everything watered. Living on the prairie, we have heavy winds that are more of a problem with raised beds because they dry out faster than in-ground gardens. However, in raised beds you can control soil and amendments better.
Another problem you may encounter are late season hungry insects that will decimate cabbage and other brassicas. There are two great ways to handle these hungry critters. Plant a trap crop. Certain varieties of cabbage work well to keep cabbage butterfly larvae away from other crops. Or, you can use a row cover with hoops. This doesn’t work perfectly, but it helps. There are also stupid spotted cucumber beetles. Floating row covers do help with these too. I don’t spray for anything. Instead, I try to wait them out. Cooler weather is coming. Soon, insect pests get sluggish and die.
I sowed my seeds in late August and early September so the fall vegetable garden would be up and growing before the garden tour we had in October. Almost everything came up well except some of the lettuces. One red lettuce I sowed is just now getting larger so I transplanted several plants to grow in our new cold frame.
Yes, I enjoyed my other cold frame so much that I put another into use. I transplanted some of the smaller curly kale in there too because I thought about what Niki Jabbour from The Year Round Veggie Gardener and Savvy Gardening says about winter gardening. We don’t really grow in winter. There isn’t enough light, but we do harvest. Best to start with larger plants before we lose the light. In the other cold frame, some of the spinach is getting crowded out by the broccoli raab so I transplanted it too.
In the new cold frame we have, spinach, red lettuce, kale, and bright green lettuce. In the other cold frame is ‘Cosmic Purple’ carrots, parsnips, broccoli raab, lettuce and spinach. There are also some errant mustard greens that are trying to take over. I planted and harvested the mustard last year, but some of it went to seed, and I now have more.
Do you grow anything in cold frames? If so, please share with me your stories. I’d like to hear of your successes. I probably won’t do broccoli raab in there again. It grows too large for the cold frame top and is just now making the edible flowers. The foliage is crazy big.
If you’d like to know more about how we built the first cold frame, it’s all in my book, The 20-30 Something Garden Guide: A No-Fuss, Down and Dirty, Gardening 101 for Anyone Who Wants to Grow Stuff.