Category Archives: Garden Advice

What to Grow through Very Hot Summers

“Heat-tolerant” and “drought-tolerant” are phrases to look for when selecting the best varieties to grow where summers are very hot. Humidity, especially warm, humid nights, leads to fungal diseases, so it’s also good to look for fungal disease resistance.

Some plants continue producing even during periods of extreme heat and humidity or heat and drought. Here are some of our recommendations:

ozark pink tomatotromboncino squashcrimson sweet watermelon

Beans: If you want green beans and shelling beans throughout the summer, it’s best to expand your repertoire to a few different species. The common green bean, Phaseola vulgaris, doesn’t handle drought or high temperatures. But lots of classic Southern beans love our high-heat summers! Try growing Southern Peas (Cowpeas) like Whippoorwill, White Acre, and Pink Eye Purple Hull. Asparagus Beans (Yard Long Beans) also love heat and humidity – they’re slightly firmer than green beans and quite a bit longer. They’re commonly used in Thai curries. Green Pod Red Seed is the classic, reliable heirloom. If you’re in the Deep South, Chinese Red Noodle takes advantage of the long season and is more heat tolerant. Lima Beans (Butterbeans) are generally very reliable in heat, humidity, and drought.

Tomatoes: Look for tomatoes that come from the Deep South, especially those bred by the universities. The large red slicer Tropic VFN (from the University of Florida) produces through very hot summers.  Ozark Pink VF (from the University of Arkansas) is highly recommended for very hot climates. These blemish-free medium-sized tomatoes have very bright, crisp flavor. For market growers looking for reliability in heat and humidity, Neptune (also from the University of Florida) is a great choice. This medium-large red slicer recently did very well in trials conducted at the University of Georgia.

Eggplant: Take advantage of your summer heat by growing an eggplant that requires it: the flavorful French/Italian heirloom Listada de Gandia thrives in hot weather.  The better known heirloom Black Beauty is also dependable in the South. The long, narrow Asian eggplants like Ping Tung Long also produce well through intense heat.

Peppers: Nematode resistant bell peppers are the best choices for Southern gardeners. Carolina Wonder and Charleston Belle are both excellent. Hot peppers generally thrive in heat and humidity. (Lots of hot places use hot peppers in their cuisines – perhaps because these plants grow so well in hot climates!) Sweet, spicy Aji Dulce peppers have an unusual, complex flavor, with just a hint of heat. They’re generally unaffected by pests and diseases, but they take a little longer to mature than most peppers.

Cucumbers:   Find out which diseases are problems in your area and use the resistance codes to help you choose what to grow. Little Leaf H-19 (from the University of Arkansas) has excellent disease resistance and is well adapted to very hot summers. It’s classified as a pickler, but it’s also very tasty sliced and in salads. Ashley is a slicer particularly recommended where disease is a problem, but my favorite choice for a heat-loving slicer is Suyo Long (the long, slender fruits are best grown on trellises).

Summer Squash and Zucchini: We recommend growing Moschata type summer squash if you have trouble growing summer squash and zucchini in your hot climate. The Moschata types have better pest and disease tolerance and produce well straight through very hot summers. Tromboncino summer squash has the extra advantage of also making excellent squash blossoms for stuffing. Waltham Butternut winter squash can be harvested small (3-5”) for eating like summer squash.  (Moschata types need nights above 60 degrees F to grow well.) You might also try edible Luffa gourds. When harvested small, they’re a great summer squash alternative.   

Winter Squash and Pumpkins: As with summer squash, we recommend choosing moschata types when growing winter squash and pumpkins in the South. (Avoid pepo and maxima types.) Pretty much any moschata will thrive through hot summers, but particularly productive varieties are Seminole Pumpkin, Waltham Butternut, and Tan Cheese. Green-Striped Cushaw is from another type of squash altogether (argyrosperma or mixta). We know Southern gardeners who won’t grow anything but Cushaws: they’re super productive through our summers and their seeds are very large and tasty. The flesh tastes a little different than most winter squash and not as sweet, but it can be used in pies if you add extra sweetener.

Melons: Top Mark, Sweet Passion, and Kansas all have extra disease and/or pest tolerances. Edisto 47 is particularly recommended for hot, humid summers where fungal disease is an issue. Missouri Gold produces well through droughty conditions.

Watermelon: Crimson Sweet and Strawberry watermelon are good choices where heat and humidity make fungal diseases a problem.

Okra: Choose older and heirloom varieties of okra with deeper root systems. The deep roots give these plants resistance to nematodes and improved drought and heat tolerance, but these varieties also usually take longer to mature. Gold Coast is a variety particularly noted for its deep roots, but Stewart Zeebest and Beck’s Big Buck also are excellent heirlooms for the Deep South.

Greens: Lettuce is very difficult to grow outside when it’s hot, and spinach is pretty much impossible, but don’t give up on summer salads and cooked greens.

For cooked greens, Swiss chard and turnip greens are the best choices in the South. These plants are biennials, which means they usually won’t bolt (go to seed) until they’ve gone through their first winter. So they stay tender and mild all summer. Sweet potato greens, New Zealand summer spinach, and the young leaves and shoot tips of squash can all be used for cooking greens.

For salads, buckwheat leaves add an unusual nutty flavor. Grain amaranths like Mayo Indian are very productive in high heat and humidity. Many heat-loving herbs add flavor to salads, including roselle, anise-hyssop, dill, & basil.

We strongly recommend Red Malabar summer spinach to anyone who hasn’t tried growing it yet. The crisp, slightly succulent leaves stay mild in high heat and maintain healthy growth all summer. The gorgeous red vines need to be trellised or caged, but this keeps the leaves clean. They’re excellent as cooking greens and in salad mixes.

What to Sow in January

Written by Lisa Dermer. Source materials include conversations with Ira Wallace.

As the year begins we’re eager to start sowing seeds, but nervous about starting too early and having big, leggy transplants and nowhere to plant them. There are lots of crops we can and should start in January: bulbing onions, rhubarb, artichokes, celery and celeriac, parsley, and spring flowers (like poppies, chamomile, and evening primrose). Long season hot peppers (like habañero) can be started at the end of January; peppers are generally slow to germinate. We’ll start our seeds indoors, or outside in cold frames or the hoophouse, for transplanting later in the spring.

Be aware of when you want to plant and decide when to sow transplants by counting back from then! Overly large transplants suffer greater transplant shock and may have reduced yields. Brassicas like kale, collards, cabbage, and broccoli should have 3-4 true leaves and be about six weeks old when you transplant. Tomatoes and eggplants also need about six weeks, and peppers need 8-10 weeks. In our area we transplant most brassicas in mid-March, so we’ll wait until early February to sow. We provide recommended planting dates (PDF) >>

Sow bulbing onions for transplant now if you haven’t sown them already. Those in the lower South should have already sown Short Day Length bulbing onions, like Vidalia, last fall. In-between areas like us will have the best results growing Long to Intermediate Day Length bulbing onions, and starting them in December or January. Transplant out when they’re still thinner than a pencil! Read about growing bulbing onions >>

Artichokes and rhubarb should be sown in January and grown in cold frames to vernalize. They need the exposure to colder temperatures now to put on much growth later.

Winter has been warm all over the South: we’ve been sowing greens in cold frames and the hoophouse every couple weeks since fall. You can sow a variety of winter hardy greens (spinach, cress, mustard greens, arugula) throughout January. Remember, plants grow slowly in winter’s low light – even in warm greenhouses your starts may not put on much growth until the sun is stronger.

There’s still work to be done outside, even if it’s too early to be putting out plants. On nice days, prepare your beds if the weather is warm and dry enough. Then cover with mulch or row cover (prevent erosion on bare soil!) until you’re ready to plant. And don’t forget to look after your perennials – most fruit trees need pruning in winter, before they start to bud.

Request a free copy of our new catalog if you haven’t received one yet. We do expect to run out of some varieties, so order early while things are still in stock.

Happy winter gardening!

Cover Cropping for Unpredictable Weather

buckwheat cover crop

We’ve had some very heavy rains this summer, and it’s reminding us why planting cover crops is so important this fall. Cover crops increase the carbon content of our soils through root growth, root sloughing in response to mowing, and when we incorporate vegetative growth into the soil, directly tilling the plants under or composting first.

Soils with higher carbon content drain better, which prevents flooding and keeps our crops from getting “soggy feet.” Water saturated soils create lots of problems for plant growth – they quickly become oxygen depleted, and plants respond by growing new roots to hunt for oxygen. This root growth is costly – it means the plants aren’t growing the greens or fruits we want. And the new roots generally form at the plant base, on the soil surface, where there’s plenty of oxygen available, while deeper roots may die. The result is shallow-rooted plants that are more susceptible to drought and more vulnerable to wind and other disturbances.

Carbon-rich soils are more resilient to dry conditions as well as wet. In addition to increasing soil porosity and drainage, higher carbon content also lets soils hold more water. Deep rooted grasses like rye are especially good cover crops for increasing the carbon content of the subsoil, so that plants can be scavenging deeper water reserves even when the surface layers have dried out.

buckwheat cover cropWell established cover crops will help prevent our soil from being washed away by winter rains, but they also prevent leaching of soil fertility. Nitrogen and other nutrients still available in the soil after summer and fall crops can’t be leached out of the soil by heavy rains when tied up in cover crops like oats and rye.

We plant quick-growing winter rye in most of our fields. We mix hairy vetch with the rye to add nitrogen to the soil, but only in places where the soil won’t be worked until late spring (vetch sprouts now, but puts on most of its growth in late spring). Where we plan to have early spring crops (like potatoes, peas, and early spring greens), we plant Hulless Oats. Temperatures below 10°F kill our oat cover crops in January here, and the residues are easier to work into the soil for early crops. Red Clover, Crimson Clover, and White Dutch Clover are also good winter cover crops, but are slower to establish than other types – so sow clovers at least 40 days before your average first frost.

Good luck with your cover cropping – it’s one of the most important things you can do to sustainably manage soil fertility.