Thinking Outside the Windowbox

Yes, the Summer Heat is Nearly Upon us and Traditional Garden Veggies are Months Away from their Planting Season. But for these Florida Summer Fruits & Veggies, now is the Right Time

By Kenneth Setzer

May 2018

There are all kinds of heat- and deluge-tolerant, edible plants we can grow with little trouble here in the deep southeast summer. While the northern, more temperate regions can grow tomatoes and other vegetable staples, we must look towards the tropics for plants suitable to our torrid spring and soaking summers. 


Katuk (Sauropus androgynous) is a common leafy green throughout much of Asia. I recently picked a handful and ate them in front of my amazed coworkers. I assured them I would never eat anything that isn’t completely known to me to be edible. The next question is taste. Katuk greens taste a lot like green beans or peanuts to me—quite good. 

Sometimes called tropical asparagus, katuk forms a compact bush that can be cut down to near the soil and will regenerate. The leaves contain almost 50% protein and can be cooked like any other leafy green or tossed raw into salad. The small red flowers and fruit are attractive and used in some recipes as well. A health craze in parts of Asia encouraged consuming huge amounts of raw katuk, which led to illness for a few people. But just about any food eaten in huge quantities to the exclusion of others can be dangerous (raw lima beans, for instance). 

Katuk is a favorite of mine because it is attractive and does not need constant attention. It is easily grown from cuttings placed in damp soil or water and thrives in heat and high humidity. Small plants are sold online. Katuk likes the understory, with dappled shade, but not deep shade. It’s grown for the foliage, so a common practice after harvesting leaves is to add fertilizer for a good nitrogen boost. Manure, especially of poultry, is a good source, and it improves our sandy soil. 

A Katuk bush forms edible landscaping


Purslane (Portulaca oleracea) is a succulent, evolved to grow in dry places and tolerate periods of drought. But, unlike some other succulents, it doesn’t seem perturbed by heavy rains, poor soil and direct sun. You can find it on lawns as the weed with long, purplish red stems with small teardrop-shaped green leaves. 

Purslane is rich in alpha-Linolenic acid (an omega-3 fatty acid), vitamins A, C and B, as well as beta carotene, and plant pigments shown to have anti-mutagenic properties, meaning they may inhibit cells from mutating. As a companion plant, purslane provides ground cover, retains humidity, and the deep taproot breaks through difficult soil and extracts nutrients nearby plants can use. Since you can’t know what’s been sprayed on wild plants, I do not recommend eating purslane you find. Seeds are available online. 

Purslane is a nutritious plant


Did you know nasturtiums are edible? Tropaeolum is the genus of this tough but elegant plant (genus Nasturtium is that of unrelated watercress). The seeds you’ll find at most stores is probably those of T. majus, common garden nasturtiums. Both flowers and foliage are edible and add a little kick to salads, similar to arugula. It thrives in poor soil; if fertilized it is known to produce fewer flowers but more foliage. The neon orange flowers have been observed to “flash” against the rounded, water lily-shaped leaves in an optical illusion. A common pest to watch for is moth caterpillars, which can be hosed off. 

Nasturtiums are both boldly beautiful and edible


If you really want to grow tomatoes in the summer, try the Everglades Tomato (Solanum pimpinellifolium), naturalized to South Florida. These are small currant tomatoes — about the size of a large pea — but to me very flavorful. They are indeterminate and like to sprawl, but the small fruit is light and won’t necessarily need a support to keep off the ground. These thrive in our summers, and while short-lived they produce so much fruit that some is bound to fall to the ground and regrow. It has volunteered unexpectedly in parts of Fairchild (even in shade), but plants can be found at native plant nurseries. 

I’ve also had minor success with Florida 91, a heat-loving, determinate tomato variety growing to about 3 feet. They’re known to resist cracking from intense rains, but problems come from tomato hornworms that devoured my plant mercilessly. Soapy water helps kill them. Patio Choice Yellow Hybrid Tomato is another option and is designed for pots as it is determinate and stays compact. The cherry-sized fruit are delicious and ornamental. Provide at least 6 hours of direct sun and well-draining soil. 

Everglades tomatoes sprawl inches above the soil


Nearly any mint provides seasoning, variety, and tolerates summer. Grown easily from seed or bought as seedlings, Mentha species need shade from our harsh midday sun, and also prefer moist, rich soil — a good candidate for pots. Mentha spicata, spearmint, has been crossed with other species to produce peppermint, chocolate mint, and citrus-flavored mints. 

Try as we might to grow basil (Ocimum basilicum), all the sweet varieties are prone to downy mildew, and there’s not much we can do about it. Red or Thai basils are less susceptible. You can, however, buy a sweet basil plant and keep cuttings in water, thus increasing your supply a little as the original dies. But I’d be remiss if I forgot to mention that we have a native basil, Ocimum campechianum. Also called “least basil,” it is hard to find and listed as endangered in South Florida, but is more common in the West Indies and tropical America. 

Mint is easy to grow, but prefers shade


Lastly, peppers grow well in summer. From sweet bell peppers to habaneros, peppers like full sun and well-draining, nutrient-rich soil. Start from seeds in small containers to avoid the small seeds washing away, or buy plants. General fertilizer is fine, but avoid one with excess nitrogen once fruits appear. Even if you don’t love eating hot peppers, they are beautiful ornamentals in shades of green, orange and deep red. 

Spicy to eat, beautiful to behold, peppers like hot summers

Kenneth Setzer is a writer for Fairchild Tropical Botanic Garden