What to Plant With Lettuce: Lettuce Companion Plants (and What to Avoid)

Lettuce is small, quick and shallow-rooted, which makes it one of the best fillers in a vegetable garden. It can be tucked between slower crops, harvested before they need the space, and resown every couple of weeks. The main enemy is heat, which makes lettuce bolt and turn bitter, so the most useful companions are often the ones that give it a bit of afternoon shade. Here is what extension sources list and how to use it.

Good companion plants for lettuce

Tomatoes

Oregon State and Maryland Extension both describe lettuce tucked behind or between tall tomatoes, where it gets summer shade and bolts later. University of Maryland Extension also recommends interplanting lettuce between rows of later-maturing crops like tomatoes and broccoli as a space saver. See what to plant with tomatoes.

Carrots and radishes

Carrots, radishes and lettuce are all listed companions and all go in early in spring. They work at different depths: radishes are pulled within weeks, lettuce is cut next, and carrots finish last. This trio is the base of our cool-season bed. More in what to plant with carrots. See what to plant with radishes for radish timing and companions.

Cucumbers

Virginia Extension lists cucumbers and lettuce as companions. A cucumber trellis on the sunny side of a lettuce row can shade it as summer heats up. See what to plant with cucumbers.

Strawberries and dill

Strawberries are a listed lettuce companion and make a low, tidy border. Penn State Extension notes that dill draws aphid predators to greens, so a few dill plants near the lettuce can help, as long as the dill is kept away from carrots. Penn State Extension suggests fennel near greens for the same reason; see what to plant with fennel. Cilantro does the same job and is sown at lettuce time; see what to plant with cilantro.

What not to plant with lettuce

Onions and garlic are the plants Virginia Extension lists as incompatible with lettuce. Plenty of gardeners grow them near each other anyway, and evidence for most companion effects is thin, but the simple fix is to keep the onion family in its own row or bed. Onions get along with carrots, tomatoes, peppers and the cabbage family instead; see what to plant with onions. Every pair to separate is in our keep-apart chart.

Use taller crops for summer shade

Long days and summer heat push lettuce to send up a seed stalk (bolt) and turn bitter. University of Maryland Extension suggests planting later lettuce where sweet corn, staked tomatoes, pole beans or deciduous trees shade it during the hottest part of the day, and using shade cloth in summer. Lettuce tolerates partial shade of about four to six hours of direct light a day, though early spring plantings grow fastest in full sun. Slow-bolting or heat-resistant varieties, such as oakleaf types, stretch the season further.

Lettuce types and spacing

• Leaf lettuce: the easiest and fastest. Thin to four to eight inches apart, or grow in a wide bed thinned to four to eight inches on all sides.
• Butterhead (Bibb, Boston): loose heads; small varieties suit succession planting. Space like leaf lettuce, up to about 10 inches.
• Romaine (cos): upright heads, relatively easy to grow, similar spacing.
• Crisphead (iceberg): the hardest, because it needs a long cool season. Space 12 to 15 inches apart and start slow-bolting varieties indoors.

Spacing ranges are from University of Maryland Extension; closer spacing works if you plan to harvest young. In a square-foot grid, Clemson Extension fits four leaf lettuces or one head lettuce per square; see square foot gardening.

A simple lettuce bed layout

1. Tomatoes or a cucumber trellis along the north side.

   Listed lettuce companions; they will throw some afternoon shade as summer arrives.

2. Two rows of lettuce in front.

   Sown a couple of weeks apart for a steady harvest.

3. Radishes and carrots in the next rows.

   Listed companions with different harvest times.

4. Strawberries along the south edge, with a dill plant at one end.

   Keep the dill away from the carrots.

Keep onions and garlic in another bed. Our raised bed layouts include a 4×4 cool-season bed with lettuce.

When to plant lettuce

Lettuce is a cool-season crop that handles light frost. Sow leaf and butterhead types as soon as the soil can be worked in spring, and again in late summer for fall. University of Maryland Extension notes that three-to-four-week-old transplants give earlier harvests and skip thinning. Our planting calendar turns your frost date into indoor-start and outdoor windows. Our what to plant in fall guide has fall dates by region. For dates by frost, sowing every 10 to 14 days and fall lettuce, see when to plant lettuce.

Watering and harvest

Lettuce has shallow roots, so cultivate carefully and use an organic mulch to hold moisture and keep the soil cool. Water lightly and often for fast, tender growth, but do not overwater, and water overhead only in the morning so leaves dry during the day.

Leaf lettuce can be picked once plants are five to six inches tall; take the older outer leaves first. For cut-and-come-again greens, cut plants just above the soil when they are 6 to 10 inches tall, and they will often regrow for a second cut two to three weeks later.

Lettuce in containers

Lettuce is one of the best container vegetables. A wide, shallow pot or window box with drainage holes, a quality potting mix and regular watering is enough. Move containers into partial shade as summer heats up to delay bolting.

Frequently asked questions

What grows well with lettuce?

Extension-listed companions for lettuce in our checker are carrots, cilantro, cucumbers, dill, fennel, radishes, strawberries and tomatoes. The table on this page explains why each pairing works.

What should you not plant with lettuce?

Our sources list garlic, onions and parsley as poor neighbors for lettuce.