How to Plant, Grow, and Care for Bibb Lettuce

While all homegrown lettuce is delicious, bibb lettuce’s buttery leaves are a special treat. If I had to pick one type of greens to grow at home, it would be this one. Not only are the tender leaves sweet, but the difference between just-harvested heads and those shipped across the country is remarkable.

Bibb lettuce, also known as Boston or buttercrunch, is versatile in the kitchen. The soft leaves pair well with peas and radishes in spring salads and hold up well in wraps.

Since the fragile lettuce didn’t hold up in transport, it was slow to spread in popularity. Eventually, growers across the country began to grow Mr. Bibb’s lettuce and produce similar yet different varieties. By the 1960s, it was widely available and well-known. 

Today, people may refer to any soft, buttery head as bibb. Other common names include Boston and buttercrunch.

Characteristics

Bibb’s soft, tender leaves make it stand out from other types of lettuce. The wrinkled leaves are arranged in a round head, and the large outer leaves blanch the tender inner greens. The outer leaves often lay flat on the soil surface.

You can find both red and green varieties of bibb lettuce. Red types often have green leaves with maroon edges.

Native Area

This crop originated in the Mediterranean, and varieties with buttery leaves were later developed in Europe. However, John B. Bibb created Bibb lettuce in Kentucky.

Planting

Since this variety grows best in the cool weather of spring and fall, mid-spring and late summer are often the best planting periods. Planting at these times gives the crops time to mature before high heat and heavy freezes arrive.

Using protective frost cloth and/or a cold frame can help you extend your planting season into the beginning and middle of fall. However, since decreasing daylight will slow plant growth, get your seedlings in the ground by October to ensure that they grow in size up before winter arrives.

Transplanting

Transplanting ensures proper plant spacing and allows you to get a jump start on the spring growing season. You can either purchase seedlings from a garden center or start your own.

Although mature heads can tolerate light frosts, seedlings are more susceptible to cold damage. Therefore, I recommend waiting until after your last frost to get plants in the ground. If you’re aiming for a fall or winter harvest, transplant your seedlings in the late summer or early fall.

Provide a foot of space between each seedling. You can also interplant bibb lettuce with crops like tomatoes, scallions, and other upright plants. The low-growing greens will help shade out weeds, and the taller plants will provide dappled shade.

Growing From Seed

Growing lettuce from seed gives you access to varieties you may not be able to find in garden centers and nurseries. It allows you to plant your heads exactly when you want them so you can stay on track with your planting calendar. I recommend starting seeds in cell trays and later transplanting them into your garden.

Sow your seeds in soil blocks or cell trays four to six weeks before you plan to transplant them. Always use a well-draining seedling mix and plant the seed no more than a quarter of an inch below the soil surface. Water the soil until moist, then set the seeds somewhere between 60-70°F (16-21°C).

The seeds should germinate within a week. As soon as you see the seedlings emerge, move them to an area that receives at least ten hours of direct light. You can use a grow light if you don’t have a bright spot.

Keep the soil slightly moist as the seedlings grow—plan to water about once a day. Within four to six weeks, they should be a few inches tall and ready to transplant outdoors. Make sure to harden them off to lessen transplant shock and encourage a smooth transition into their new home.

How to Grow

These buttery heads are easy to grow in large gardens, raised beds, and containers.

Light

Some gardeners think this crop’s dislike of high temperatures means it grows well in shade, but these still plants appreciate full sun. Boston lettuce grows best when the plants receive at least eight hours of direct sun. If you only have partial shade available, opt for a location that provides morning light and afternoon shade.

Water

Since lettuce has a shallow root system, it’s important to never let the top two to three inches of the soil completely dry out. Recently transplanting seedlings require frequent irrigation as they adjust to their new home, but established seedlings can go longer without water.

The frequency with which you should water your plants depends on factors including the soil type, temperature, and humidity. Rather than watering on a set schedule, check the top inch of soil and water when it feels dry.

Watering the soil surface via drip irrigation or a watering can is always preferred to overhead irrigation. Sprinklers and hoses lead to wet leaves and increase the chances that plants will develop fungal diseases. 

Soil

Bibb lettuce grows best in soil that’s well-drained and well-aerated. Constantly wet soil can spur the development of fungal diseases, especially since these tender greens sit close to the ground. The plants can grow well in clay and loam soils as long as they drain well.

Temperature and Humidity

Since this crop is sensitive to high and low temperatures, it grows best in the spring and fall. Growing temperatures between 40-75°F (4-24°C) are ideal.

When the plants experience extended temperatures above 80°F (27°C) or brief periods above 90°F (32°C), they become stressed and bolt, aka go to seed. Although bolted plants are safe to eat, they have an undesirable bitter taste.

Bibb lettuce can tolerate below-freezing temperatures, especially if the plants are slowly acclimated to cold and protected with row cover. However, the plants are unlikely to survive harsh freezes.

Fertilizing

This is a light feeder that doesn’t require much fertilizer to remain healthy. However, small doses of nutrients can support plant growth and increase yields.

Conducting a soil test is the best way to determine the amount of nutrients present in the soil. Once you have the test results, you can calculate what nutrients to apply.

If you don’t want to conduct a soil test, apply a small dose of a balanced vegetable fertilizer at planting time. This product will supply the three macronutrients (nitrogen, phosphorus, and potassium) required in large amounts. Be careful not to apply too much fertilizer since excess nutrients can harm your plants and the surrounding environment.

Maintenance

These salad heads are low-maintenance and require little outside of routine care. The small size and easy-to-grow nature make it an excellent crop for container gardeners, beginners, and kids.

Harvesting and Storage

While you can harvest at any time, most gardeners wait until the heads are mature. Most bibb varieties grow into fully-formed heads in 50-60 days, so expect to harvest after they’ve been in the ground for close to two months. Gently squeezing the top of each head lets you feel the density and determine if it’s ready to harvest.

The early morning and evening are the best times to harvest this tender green. Cut plants close to the soil surface, remove any discolored or dirty lower leaves, and store your lettuce in the refrigerator for up to a week. You can also pick a few outer leaves and allow the inner leaves to mature.

Common Problems

Bibb lettuce is susceptible to numerous diseases as well as a few pests. Since the plants’ lower leaves sit near or on the soil surface, they’re prone to soil-borne infections. Learning how to recognize and prevent common problems will help you keep your plants healthy.

Pests

Bibb lettuce is susceptible to many of the same pests that plague other lettuce types. Keep an eye out for the following and treat them as necessary.

Aphids

These tiny insects are the bane of many gardeners’ joy. Although they’re small, their rapid reproduction rate means they’re difficult to control and can quickly get out of hand. A few aphids won’t harm your plants, but these individuals can quickly balloon to a hundred pests that can cause noticeable damage.

Aphids harm plants by drinking their sap. This feeding weakens plants and also spreads harmful diseases.

In healthy gardens, natural predators often help keep aphid populations in check. Planting a diverse array of flowering crops can help support beneficial insects like ladybugs, hoverflies, and green lacewings. However, when aphid populations explode, consider treating them by spraying neem oil or insecticidal soap.

Thrips

Thrips are tiny insects with elongated bodies. Since they’re small and mobile, you may spot the damage they cause before you see the insects. Thrips pierce plant tissues and suck out the contents. In lettuce, the results are silvery leaves dotted with small dark dots of the thrips’ frass.

This damage only becomes noticeable when the plant grows, so the thrips are often gone by the time you spot silver leaves. Therefore, don’t assume that damage means you should treat your plants for thrips.

Predatory insects can help control thrips, so avoid broad-spectrum insecticides and plant a diversity of flowering plants. Thrips rarely warrant control in the home garden, but you can spray them with neem oil or insecticidal soap.

Diseases

Bibb lettuce is susceptible to numerous fungal, bacterial, and viral diseases. Its low-growing shape makes it especially susceptible to soil and water-borne diseases. Since most of these issues are difficult to treat once they appear, prevention is often the best strategy.

Downy Mildew

Downy mildew often occurs in the cool and wet conditions present in spring and fall. Light green patches on the tops of lettuce leaves are the first signs of infection. Eventually, the undersides of the leaves turn white, and the spots turn brown.

You can prevent downy mildew by avoiding overhead irrigation and utilizing plant spacing that encourages good airflow. Growing downy mildew-resistant cultivars will also decrease the likelihood of infection.

Anthracnose

In most plants, anthracnose is caused by fungi in the Collectotrichum genus. However, the fungus Microdochium panattonianum is the causal agent for anthracnose in lettuce.

This fungus causes yellow or brown, round, water-soaked lesions on lettuce leaves. The foliage in the center of these spots eventually falls out, leading to the nickname shot hole.

Anthracnose is difficult to treat once it occurs, so preventing the disease is your best option. Use drip irrigation to keep plant leaves dry and practice crop rotation to avoid a buildup of the fungus. If you spot anthracnose on lettuce, remove the infected plant immediately.