Many gardeners don’t thin looseleaf lettuces. They are often harvested young, and multiple times in a season reducing their chances of getting fungus or mold. As starts grow the weaker ones will die out naturally providing space for stronger plants.
If you are transplanting looseleaf lettuce starts, plant them 2-4 inches apart. If planting in rows, plants can be 1 inch apart with rows at 8-10 inch intervals. One rule of thumb for row planting leaf lettuce is 10 plants per foot.
Butter lettuce will form semi-firm heads if given the space to do so. You can pack them together and treat them as a looseleaf lettuce, or space them out like you would a heading lettuce and grow them larger.
If a head is your intent, space them 6-8 inches apart. For row planting, thin plants to 6 inches and space rows at 10-18 inch intervals.
Crisp Head Lettuce
Crisp head lettuces require the most amount of space and are the most difficult to grow. These varieties need extra care in order to produce the firm yet mild tasting heads that are often on grocery store shelves. Giving each plant the room it needs to be as healthy and robust as possible is essential.
Space crisp head lettuces 12-18 inches apart. Romaine varieties that grow up more than out can be spaced as close as 6 inches. For row crops, space plants 6-12 inches apart in rows at 18-inch intervals.
Here is a quick reference guide to spacing lettuce:
- Looseleaf Lettuce – 2-4 inches apart
- Butter Lettuce – 6-8 inches apart
- Crisp Head Lettuce – 12-18 inches apart
Some lettuces grown in hydroponic systems are placed much closer together. Because the roots don’t have to compete for nutrients, they don’t require the same amount of space. Crisp head varieties are grown as close as 4 inches apart in hydroponic tables.
Lettuce is popular to grow in containers because it can be packed closely together. As you harvest the outer leaves of looseleaf and butter lettuces, the plant continues to produce from a central crown. This feature allows you to keep harvesting all season long, and as you do this you’re also creating more space for the new leaves to grow into.
Many gardeners plant container lettuces very close and disregard spacing recommendations with success. Experiment with what works for you and when in doubt follow the seed packet instructions.