Red Leaf Lettuce (Lactuca sativa) is a general name for dozens of varieties that produce semi-frilled loose-leaf lettuces and are members of the Asteraceae family. Red leaf lettuce was first described in 1753 and flourished heavily in the late 19th and early 20th centuries. It is small to medium in size and grows in an elongated shape with a narrow base that fans out to a broad, curly loose top.
Red leaf lettuce can grow up to thirty centimeters in height and is one of the most commonly planted lettuce in the world. The leaves are dark burgundy to red, and most times, they taste bitter when the leaves mature. Red leaf lettuce is low in sodium and calories and has a high water and fiber content, making it a good food product for weight loss.
Additionally, red leaf lettuce is packed with antioxidants such as beta carotene, anthocyanins, and Vitamin C, which protects us from various damages. Beta carotene converts into Vitamin A in our body, which helps improve vision and reduces the risk of age-related macular degeneration.
While anthocyanins are a group of flavonoid antioxidants that helps fight inflammatory agents and lower cholesterol levels, vitamin C, on the other hand, reduces the risk of chronic diseases.
| Common Name | Red Leaf Lettuce |
| Botanical Name | Lactuca Sativa |
| Family | Asteraceae |
| Plant Type | Annual, Vegetable |
| Size | 30 cm in height |
| Sun Exposure | Full sun, partial sun |
| Soil Type | Light, well-draining soil |
| Soil pH | Acidic, neutral (6-7) |
| Bloom Time | Seasonal |
| Hardiness Zone | 6-10 USDA |
| Native Area | Europe |
How To Grow And Care For Red Leaf Lettuce
Red leaf lettuce can be planted in early spring as soon as the soil can be worked on.
Growing Red Leaf Lettuce
If you are planting red leaf lettuce in a container, using a soil-less medium is advisable as it doesn’t hug the roots of the plants. Ensure the planting site is rich in organic compost matter to encourage tender and tasty growth.
You can also plant red leaf lettuce among warm-season vegetables such as tomatoes. In this case, by the time the lettuce is finished in early summer, the warm-season vegetables will start growing and be able to take over the place.
1. Sowing
Direct seed red leaf lettuce in early spring. To be on the safe side, prepare the seed beds the previous fall by working in manure or compost to leave a fine seed bed. Remember to sow the seeds at a very shallow depth by covering them with a thin layer of growing medium.
Indoors: Start 3-4 weeks before planting outside. Sow at least 2-3 seeds per cell/pot, thinning to one per cell/pot. Then provide 60-70 degrees Fahrenheit soil temperatures.
Outdoors: Sow seeds in spring when the soil temperature reaches at least 5o degrees Fahrenheit. Depending on the size you want, either baby to full heads. Sow 1″ apart, thin to 6-12″.
Keep the soil moist during germination and sow every 2-3 weeks for an extended harvest period. For baby greens, sow heavy seeded rows every 10-11 days using ½ oz.
Note: When the seedlings are an inch tall, thin them to a distance of 5 or 6 inches apart. You can also transplant them to a new spot in the garden to space them properly. Otherwise, your red-leaf lettuce will only form part-sized heads. Therefore, give them room for the best large, succulent heads.
2. Direct Seedling
Sow seeds 1/8 to ¼ inch deep as they need light to germinate. Lightly scatter the soil onto the area, then spray with warm water and wait.
3. Transplants
Sow seeds in 1-inch cells 3 to 4 weeks before transplanting outside. Harden the seedlings by reducing water and temperature for three days before transplanting.
Caring For Red Leaf Lettuce
For optimal growth, red leaf lettuce needs proper care and maintenance.
1. Light
Red leaf lettuce needs at least six hours of direct sunlight on most days but will also grow in partial sun and some shade in warm climates.
2. Soil
Red leaf lettuce thrives best in light soil, rich in organic matter, and well-draining. A neutral to slightly acidic soil ph of 6.2 to 6.8 is also preferable.
Red leaf lettuce seeds are pretty small, so ensure the seed is well-tiled; otherwise, clods of dirt will prevent germination. If growing in your backyard plot, add plenty of fertilizer and materials to enrich your local soil.
3. Water
It’s best to water your red leaf lettuce regularly throughout the week anytime the top inch of the soil feels dry. The plant will tell you when it needs water; you need to look at it.
If the leaves are wilting, sprinkle them anytime, even in the heat of the day, to cool them off and slow down the transpiration rate. Row covers can also help keep the red-leaf lettuce from drying in the sun.
4. Fertilizer
To help promote healthy, vigorous leaf growth, use a fertilizer high in nitrogen starting three weeks after planting, following label instructions.
5. Foliar
The application of foliar sprays contains nitrogen and will keep red leaf lettuce healthy and strong.
6. Mulching
Use mulch around the plant to keep weeds down and to protect the plant’s shallow root system from damage.
7. Rotation
Plant red leaf lettuce with a legume crop like peas or beans to replenish soil nitrogen levels.
8. Companions
Red leaf lettuce grows well with carrots, collards, onions, strawberries, beets, cucumber, radishes, marigolds, borage, chervil, Florence fennel, and leeks. Avoid parsley and celery.
9. Pollination
Red leaf lettuce is a self-pollinated crop.
10. Protection from Pests and Diseases
The main pests and red-leaf lettuce diseases include the mosaic virus, powdery mildew, earwigs, aphids, cutworms, slugs, snails, and caterpillars.
Aphids can be prevented by growing companion plants, knocking them off with water spray, and applying insecticidal soap. You can also introduce native species of predatory insects, such as praying mantises, ladybugs, or braconid wasps that will feed on red-leaf lettuce.
Lettuce mosaic virus is an essential virus affecting red leaf lettuce. It can be prevented by using row covers.
Cutworms are the larvae of various species of moths in the Noctuidae family. They chew on the stems of plants, cutting them down at the soil level. They can be prevented by using chemicals sparingly and introducing beneficial predatory insects such as praying mantises, ladybugs or lacewings, as they will hunt the larvae as they hatch.
Powdery mildew can be prevented by spraying plants with one teaspoon of baking soda dissolved in 1 quart of water.
Earwigs can be prevented by using a tuna can filled with ½ inch of fish oil and sinking it into the soil so that the edge is slightly above the ground level.
Snails, slugs, and caterpillars also love to prey on red-leaf lettuce leaves. They can be prevented using insecticides, traps, organic bait, and handpicking.
Note: If you notice your red leaf lettuce beginning to get brown and curl, it could be suffering from a psychological condition known as tip burn. Tip burn is often seen on red-leaf lettuce when the moisture is inconsistent.
Harvesting And Storing Red Leaf Lettuce
Harvesting red-leaf lettuce is an invitation for the plant to grow more leaves. You can harvest red leaf lettuce by removing the outer leaves so that the center leaves can continue to grow. All you need are sterilized scissors or pruning shears, golden gloves, and a basket for this process.
Then spread a leaf from the outer circumference of the plant and snip it close to the base. Continue to work around the outer edge of the lettuce head until you have the amount of lettuce you want.
Storage
You can store your red-leaf lettuce in the refrigerator for up to 1 week. When ready to use, put the harvested lettuce in cold water for a few minutes. Then place it in a salad spinner or towel and spin the spinner to remove the water from the lettuce.
Note: If the leaves are wilted, put them in a bowl of cold water with ice cubes and soak them for 15 minutes.
How To Delay Red Leaf Lettuce From Bolting
Bolting is a common problem caused by warm temperatures or changes in day length. This usually happens when the daytime temperature pass 75 degrees Fahrenheit at night and its more than 60 degrees Fahrenheit at night.
When your red leaf lettuce starts to bolt, it produces a central stem, seed stalk, and the leaves become bitter. To delay bolting, cover the plants with a shade cloth so that they get filtered light. Also, ensure you maintain watering throughout the warmest parts of the growing season.
Frequently Asked Questions
1. Can red leaf lettuce be grown in pots?
Red leaf lettuce has shallow roots, so it’s easy to grow them in pots, and it will extend the growing season.
2. Does leaf lettuce come back every year?
Red leaf lettuce is one of the few plants that return to your garden yearly by spreading their seeds.
3. How long does it take to grow red-leaf lettuce?
It takes 45-55 days for red leaf lettuce to reach maturity after germination.