What would a garden be without lettuce and tasty salad greens? With a myriad of leaf and head lettuces to choose from, why not give them a try? Add spicy and bitter greens for a gourmet treat.
This article discusses how to grow cool‐season salad greens including looseleaf, romaine, butterhead, and crisphead lettuces, as well as endive, escarole, and radicchio. The companion article “Growing Leafy Greens: Part 2” discusses how to grow spinach, Swiss chard, and leafy brassicas.
Plant lettuce in the spring as soon as the soil can be worked. If it’s too early in the season, the ground is either frozen or too soggy. One test for readiness is to pick up a handful of soil and squeeze it. If it crumbles like chocolate cake, it’s ready.
Lettuce and leafy greens like rich, well‐drained soil with a pH between 6.0 and 7.0. Work two inches (5 cm) of compost into the soil before planting. Adding nitrogen to the soil will also benefit leafy greens. (See the article on “Soil and Amendments” for details.)
Lettuce can be directly seeded into the garden, and either planted in single rows or broadcast in wide rows. Plant seeds from 1/8 to 1/2 inch (.31 to 1.25 cm) deep, according to packet directions. Don’t plant lettuce seeds too deeply: they require light (and constant moisture) for germination. Plant spacing is listed under each type of lettuce. Many leafy greens have shallow roots, so hoe carefully. Keep soil consistently moist.
Beat the Heat
In the heat of summer, cool season greens such as lettuce tend to “bolt”, or go to seed. Once a plant shows signs of bolting ‐ growing vertically with a seed stalk in the center, it becomes bitter and unpalatable.
Shading lettuce in the hot weather may prolong the harvest. Try planting in partial shade or under taller plants, such as a row of staked tomatoes, corn, or pole beans. Some growers use shade cloth to block as much as 45% of the heat.
Looseleaf lettuces are easier to grow and quicker to harvest than head lettuces or romaine. Looseleafs can be harvested four weeks after planting from seed, even sooner from transplants. Sow seeds every one to two inches (2.5‐5 cm). Thin to six to ten (15‐25 cm) inches apart. For a long harvest, plant varieties that are slow to bolt, such as ‘Simpson Elite’ (48 days) and ‘Red Sails’ (40‐45 days).
Romaine lettuces are slower to bolt than crispheads or butterheads, but faster than looseleafs. Plant romaine six to ten inches (15‐25 cm) apart with 18 to 24 inches (46‐61 cm) between rows. Varieties of Romaine include ‘Paris White Cos’ (70 days) and ‘Rouge d’Hiver’ (60 days).
Butterheads and crispheads don’t do well in summer heat, but they do stand up to droughts and dry soil better than looseleafs. Plant butterheads six to ten inches (15‐25 cm) apart with 18 to 24 inches (46‐61 cm) between rows. Popular varieties include ‘Buttercrunch’ (75 days) and ‘Four Seasons’ (45‐55 days).
Crisphead lettuce needs a long, cool growing season and can be difficult to grow in many home gardens. It bolts easily in summer heat and most varieties take much longer than leaf lettuce to mature. One solution is to set out transplants early in the spring.
Plant crispheads ten to twelve inches (25‐30 cm) apart with 18 to 24 inches (45‐60 cm) between rows. The most popular crisphead is ‘Iceberg’ (85 days). ‘Rouge de Grenoblouse’ (55‐60 days) is a bolt‐resistant variety that matures quickly and can also withstand light frosts.
Endive and Escarole
Endive and escarole like cold weather. Plant endive and escarole eight inches (20 cm) apart with one to two feet (31‐61 cm) between rows. Varieties include ‘Batavian Full Heart’ escarole (80‐90 days) and curly endive ‘Salad King’ (95 days). To blanch endive, see the article “Harvesting Your Vegetables”.
Don’t grow radicchio when temperatures will be over 80 degrees Fahrenheit (26 Celsius) or it will be too bitter. Sow seeds one inch (2.5 cm) apart with 18 inches (45 cm) between rows. Thin to eight inches (20 cm) apart. Varieties include ‘Red Sunrise’ (90 days) and ‘Red Surprise’ (30 days).
Plant an assortment of lettuces and other leafy greens and perk up those salads!