(Photo Illustration – Backyard Gardener – MetroCreativeConnection – JJ Barrett)
Hello Mid-Ohio Valley farmers and gardeners! I hope everyone has survived the sweltering heat of this week in late June. I noticed lots of hay being baled this week and backyard gardeners catching up on important work. There is time to make another planting of sweet corn and cucumbers, in addition to a second crop of tomatoes.
There are many unique varieties of cool season crops which can take some heat. “Green Magic” and “Eastern Crown” broccoli, “Buttercrunch lettuce” and “Parris Island” lettuce are some good heat-tolerant varieties I recommend.
This week, I will be discussing a cool weather crop, romaine lettuce. Romaine works great in the home garden and can be used in salads, sandwiches and of course my favorite, the Caesar salad. Furthermore, it is a great source of B-vitamins and vitamin C, and contains a good amount of dietary fiber. So not only does romaine lettuce add that “crunch” factor to homemade sandwiches, it is good for you as well.
Lettuce has been grown for thousands of years and is native to the eastern Mediterranean region and western Asia. The ancient Greeks and Romans held lettuce in high regard, first for its medicinal properties, then as a food source. Many Europeans still refer to romaine as “cos” lettuce, named after the Greek island Kos which is where we presume the lettuce was originally cultivated.
Romaine (Lactuca sativa) is a lettuce that produces elongated heads. Romaine lettuce is the second most popular lettuce in the U.S., still trailing iceberg or “head lettuce.” Growing romaine is similar to raising other lettuce as it thrives in cooler temperatures and needs a lot of moisture. Fall can be a great time to grow romaine, either by transplanting or direct seeding in the garden. Romaine is more heat-tolerant than some of the other lettuces, and several newer varieties have been developed to thrive in warmer temperatures.
Spring-planted romaine may bolt (produce a flower) when the weather heats up, which is why I recommend planting lettuce in the fall. Direct seeding or transplanting in mid-August through September can produce a nice harvest. Lettuce seed is very small, so it may help to order pelleted seed for more precise sowing and ease of handling.
Many of our cool season vegetables, including lettuce, can withstand temperature dips around 25 degrees F. In addition, weed and insect pressure are usually lower in the fall. Romaine-type lettuces are 8-10 inches tall, growing upright with long, tightly folded leaves that are spoon-shaped with thick midribs. The outer leaves are medium-green in color while inner leaves are greenish-white. Outer leaves can be a bit tough, but the ribs are tender and crunchy. Varieties tend to mature in about 75 days.
Romaine lettuce grows best on fertile, sandy loam soils that are well drained with lots of organic matter. However, if you have clay loam soils that are common in West Virginia, don’t worry. Romaine lettuce is an excellent choice for growing in raised beds or containers, and we can add soil amendments like compost or rotted manure to enrich the soil.
Lettuce prefers a soil with a pH of 6.0 to 6.5 and can be grown in full sun. Lettuce transplants should be left outside for four to five days to become acclimated to outdoor temperatures prior to planting in the garden. Space plants 10 to 12 inches apart in rows that are 18 to 24 inches apart.
Lettuce is a heavy nutrient feeder and needs good fertility. Several side dressings of a high-nitrogen fertilizer may be required. Fertilize according to your soil test, or contact the extension office for advice.
There are many varieties of romaine to choose from. “Green Forest,” “Coastal Star,” “Monte Carlo” and “Little Gem” are some improved varieties to try. Heirloom favorites include “Parris Island” and the red-tinted “Cimarron.” Keep in mind romaine is shallow-rooted and needs plenty of water delivered directly to the roots. This also means nutrients need to be placed near the roots for more efficient uptake.
Romaine is susceptible to a number of foliar diseases which can reduce leaf quality, including downy mildew, powdery mildew and various fungal leaf spots. Other potential disease threats include bottom rot and drop, Botrytis gray mold and viruses.
A major problem affecting lettuce is bolting (premature flower stalk production), which can occur during persistently hot weather and long days. While romaine is more heat-tolerant than head lettuce, bolting could still be a problem. Bolting can cause a bitter flavor in lettuce, and over-mature plants can be tough.
Potential insect problems include cutworms, armyworms, wireworms, aphids, flea beetles, leafminers and leafhoppers. Scouting to monitor populations can help the grower determine when and how often insecticides should be applied. Please be cautious when using any pesticide by reading and following label directions.
Harvest romaine heads just as they start to close; waiting too long can result in bolting. Cut the romaine heads off just above the soil line and below the lower leaves, using a sharp, clean knife. Heads that are 12 inches tall with a small core are ideal but heads may be shorter depending on variety.
Lettuce is highly perishable and should be cooled and used immediately or refrigerated. Romaine will last about five days in the refrigerator. Wash lettuce thoroughly just before you are ready to use it. Do not soak lettuce in water as the water will soften the leaves.
After you wash lettuce, spin or drain it completely or blot the leaves with a paper towel to remove any excess moisture.
Contact me at the Wood County WVU Extension Office 304-424-1960 or e-mail me at jj.barrett@mail.wvu.edu with questions. Good luck, and until next time, Happy Gardening!