The high temperatures that will be with us now until October take their toll in the vegetable garden. Tomatoes set fewer fruit and snap beans produce poor-quality beans, for instance.
For some vegetables, on the other hand, the hotter it is the better they like it. As the last of the cool season crops like potatoes and onions are removed or plantings of early summer vegetables such as snap beans finish, these hot weather vegetables are ideal to plant in your garden.
Keep in mind that gardening in mid- to late summer can be more challenging than gardening in spring and early summer. Insect and disease problems are often more numerous, and you must stay on top of control.
Long stretches of hot, dry weather are not uncommon, and you will need to remember to irrigate the garden deeply as needed to keep the vegetables growing vigorously. When you water, avoid wetting the foliage if you can – use soaker hoses, for example. This can help to cut down on fungal infections. The spores of most fungi that cause vegetable diseases must land on a wet leaf to successfully grow and infect the plant.
Don’t forget to much your beds about 2 inches thick with your favorite mulch. I like to use free stuff like leaves and pine straw. A good layer of mulch provides a variety benefits.
Most importantly, mulches help prevent weeds. Annual weed seeds need light to germinate, and the mulch blocks light from reaching the soil. That’s why it needs to be thick enough. This keeps the seeds from germinating and the garden has less weeds.
Blocking sunlight from reaching the soil surface also prevents the soil from heating up. Keeping the roots cooler helps vegetables deal with summer heat.
Mulch conserves moisture and prevents the soil from drying out so fast – important during dry weather.
You could hardly have a Southern garden without okra. Plant seeds now into well prepared beds spacing the seeds 4 to 6 inches apart. Water frequently. When the seeds come up, thin the seedlings to about 12 inches apart. Production usually begins in 50 to 60 days and continues until fall. Harvest the pods frequently while they are small and tender.
Southern peas are easy, productive and delicious. Excellent varieties include Mississippi Silver, Purple Hull, Whippoorwill, black-eyed and Elite. They grow on short vines and do not require trellises.
Members of the cucumber family that can be planted now include cantaloupe, cassabanana, cucuzza, luffa, mirliton (plant sprouted fruit), pumpkin and watermelon. Although squash and cucumbers can be planted now, production is difficult during midsummer because of pest problems – particularly squash vine borers.
Our main crop medium- to large-size tomatoes are set in late April, May and June and ripen in May, June and July. Once it gets really hot, with days in the 90s and nights in the 70s, these tomatoes will set far fewer fruit as pollination is less reliable.
Tomato breeders have worked on this problem, however, and developed a number of varieties that are able to set fruit despite the high temperatures. So if you’re going to plant tomatoes this late, be sure you choose types able to set fruit in high temperatures, such as Florida 91, Heatwave II, Phoenix, Solar Set, Sun Leaper, Sun Master, Solar Fire and Talladega. Cherry tomatoes and paste tomatoes tend to continue to set fruit well during summer heat.
Disease and insect problems are often more challenging for tomatoes growing during the stressful heat of midsummer. Keep an eye out for pest problems and deal with them quickly with appropriate treatments before too much damage occurs. That really goes for all vegetables.
One of my favorites hot weather vegetables is the yardlong bean. Originating in southern Asia, it is now grown extensively in Asia and Europe and is slowly gaining popularity here in the United States. It is not as commonly grown in Louisiana as it deserves to be. Although they resemble pole snap beans, yardlong beans are more closely related to Southern peas, such as black-eyed, purple hull and crowder peas.
As with snap beans, the part of this plant commonly eaten is the immature bean pods. Harvest when the pods are smaller than the diameter of a pencil, before the seeds have filled out inside and when the pods still snap when bent – generally when about 12 to 18 inches long. You may need to harvest daily because continuous picking keeps the plants producing.
Other vegetables that can be planted now are amaranth, collards, eggplant (the long, skinny Japanese types are more productive in heat), Jerusalem artichokes, Malabar spinach, New Zealand spinach, peanuts, hot peppers, sweet peppers (Banana, Gypsy), sweet potato (slips), Swiss chard and tomatillo. This is also a great time to plant basil.
Dan Gill is a horticulturist with the LSU AgCenter. He can be reached at DGill@agcenter.lsu.edu