We vegetable gardeners face many months yet of blistering hot weather. With the passing of the solstice June 21, summer has officially just begun. And it won’t be below AC thresholds in the middle of the day until late October. Long days and the predominant south easterlies off the Gulf, are heating up the sea, the soil, our roadways and buildings. This heat re-radiates back into our air at night. So the hottest weather of the year will almost certainly be in late July or August.
Nevertheless if we are gardeners, we also need to start thinking about the fall. In the north, gardeners spend the winter mulling and planning. Here, we need to use the summer to think, plan, research, study, and even dream. As well, the shortening days gradually increase the number of hours without sun, so there is less heat absorbed to re-radiate. Sometime in late August, average hourly temperatures for 24 hours will begin to drop both because there are more hours of night and because there is less sun to build up heat. The result is a rapidly declining soil temperature, and renewed growth of many vegetables that struggle or die in nineties heat.
If you have kept your peppers alive through the heat, you will be rewarded with new flushes of flowers that by November will provide buckets of tasty fruit. Squashes too that have made it to September will set large numbers of fruits both because they like warm rather than hot temperatures, and because the vine borers stop feeding. Those of you who get small tomato plants established in July or big ones in August will have great crops in November. Pole snap beans too should be planted In July.
By August, warmth-loving quick-growing veggies can go in the ground. Plant bush snap bean seeds, Edamame edible soy seeds, and summer squash seeds. In early August, you can even get a new crop of sweet potatoes if you choose a 90-day variety like Beauregard. As well, there are many kinds of Cabbage family relatives (Brassicas) suitable for August seed planting or September transplanting. I mainly grow heirloom cabbages like Early Jersey Wakefield or some of the beautiful blue – purple Savoy varieties. We can also grow early and later broccolis, and both the gorgeous violet cauliflowers and the ordinary white ones. Brussels spouts are also possible, especially north of FM1960, but July planting from seed is best. Collards and kales (both European and Siberian) by contrast are very easy, and by far the most nutritious of any vegetable. I especially like the heirloom Green Glaze. All of these, however, need very good soil fertility. Use a balanced organic fertilizer about 1⁄2 cup per square foot or more, and re-fertilize especially if you see yellow or reddish leaves.
As with many fall vegetables, the difficult choice is between planting the seeds where they will grow and using transplants. If you plant the seeds, you will need to water daily for a while, and protect them from snails and their kin. I use shears to cut the bottoms off gallon nursery pots and circle the area where three seeds or so are planted. This keeps off birds and most snails, and tells me where to water in the searing heat. Later I cut off all but the best one.
If you grow transplants, you can keep them away from pests easily, but will need to transplant them at some point. It is not at all easy to move plants in September, so the care if anything will increase at that point. If you will be gone in late August, your only option is to try to buy quality transplants in September. Although you will have less variety choice, this option works especially if you find healthy green plants without wiry stems in three-inch wide pots.
Whether you buy or grow transplants, be careful to do the following:
1. Keep small plastic pots out of direct sun, since they heat up.
2. Plant late in the day or on a rare rainy day.
3. Construct light shade over newly planted plants and keep there until the plants are growing well.
There are many other Brassicas you can direct seed in September or October. Salad greens like arugula and mizuna can be seed started anytime, but they will taste much better in the fall than in the summer. Kohlrabi is a wonderful crunchy veggie. You eat the peeled bulbous stem, and use it like cucumber in a salad. Plant them in September or October. Daikon radishes can be used this way too, but they are much better in soups.
Finally, consider carrots for your early September garden. Get a lot of fresh seed and broadcast them thinly on top of loose soil. Pat firmly and then water every day at least until the plants are an inch or more. Thin to one-inch spacings and keep weeded.
Although planting the fall garden is because of the heat and often the mosquitoes and weeds, one of the least enjoyable tasks I do in the garden every year, its reward in September to May is incalculable. We have months on end of delicious, easy to care for, healthful produce.