Lettuce wilts in the heat. Such is the sadness of the hot summer garden that the crisp, crunchy leaves of lettuce become bitter, or worse, the lettuce decides the heat is about to kill it and frantically sends up a seed stalk, a process called “bolting.”
But there is an ancient lettuce from the Mediterranean that reached the West via Rome and is known for its ability to tolerate heat. In Italian, it is called “lattuga romana,” which became the French laitue romaine, and from that our American English name, romaine lettuce (Lactuca sativa). This lettuce grows into a tall, almost cylinder-shaped head with thick leaves and a stiff rib down the middle of each leaf. This is the crunchy lettuce made famous in Caesar salads.
For best results, sow seeds directly or transplant seedlings as soon as you can work the ground in the spring. It grows best in soil with a pH between 6.0 and 6.8. Lettuce seeds need light to germinate, so just press them into the soil surface. They should be about 1/8 inch deep, an inch or so apart in rows 12 to 18 inches apart. When your lettuce has two or three true leaves, thin the seedlings to stand 6 to 10 inches apart.
You can also plant lettuce in the spaces between taller plants such as tomatoes or okra. Lettuce has a shallow root system, so you need to keep the soil moist, but not soggy. A light mulch will keep the soil cool and hold in moisture. Fertilize with a good organic fertilizer such as fish emulsion, or, since lettuce is grown for its leaves, use fertilizers high in nitrogen, such as aged manure.
For a fall crop, plant romaine lettuce in late summer. Be sure to pick all of your lettuce before the first frost, because even though seedlings can withstand low temperatures, the mature plants cannot tolerate freezing temperatures.
One of the most popular varieties of romaine lettuce is the heirloom Parris Island Cos. It is ideal for the home garden. Parris Island is often grown for baby leaf production. This is a quick-maturing lettuce with uniform, upright green heads 8-12-inches tall that do not go to seed as quickly as some other lettuces.
For a bright-red Romaine lettuce, try Cimmaron. This is an American heirloom lettuce that goes back to the 1700s. Cimmaron red romaine has a deep-red, almost bronze color with heads up to a foot tall. Best of all, Cimmaron romaine never bolts but stays crisps all season.
Little Gem is a great-tasting romaine lettuce whose tiny heads are the perfect size for individual salads. Little Gem is great for growing your own hearts of romaine. Because of its small size, Little Gem is ideal for growing in pots or small gardens.
Plant Romaine lettuce and you will have a heat-resistant, healthy vegetable that supplies vitamins K, C and A. You can also use individual leaves as edible scoops for dips, hummus, and spreads like tabbouleh. All lettuce produces a milky liquid called Lactucarium, which has a mild opiate-like effect that has been used for centuries to aid sleep.
In the summer heat, you may wilt before your romaine does.
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Paul Barbano writes about gardening from his home in Rehoboth Beach. Contact him by writing to P. O. Box 213, Lewes, DE 19958.
