Grow and Save Lettuce Seeds
How to Grow Lettuce
Lettuce is the ultimate “lazy gardener” crop—easy to grow, forgiving, and quick to reward your efforts with fresh, crisp leaves. Whether you prefer the looseleaf types that keep on giving or the head varieties that grow into compact little salad bundles, lettuce is a great addition to any garden.
Time of Planting
Lettuce thrives in cool weather, so plant it in the spring or fall before temperatures start rising. If you plant it in the summer, expect it to throw a dramatic fit and bolt straight to seed.
Spacing Requirements
Sprinkle those tiny seeds 1/8 inch deep, about an inch apart. If you’re growing looseleaf varieties, thin them to 6-8 inches apart. If you want big, impressive head lettuces, give them a comfy 12 inches of space to stretch out.
Time to Germination
7-14 days—because even lettuce needs time to wake up and get going.
Special Considerations
Lettuce is happy to be harvested bit by bit (cut-and-come-again style) or left to grow into full heads. If you’re growing it for seed, thin plants to 12-16 inches apart and give them a little breathing room to flower. Also, when lettuce starts flowering, it prefers drier conditions, so go easy on the overhead watering unless you want sad, soggy seeds.
Common Pests and Diseases
Aphids, botrytis, and lettuce mosaic virus are all common problems. Birds, too, like to sneak in and snack on young seedlings. Keep an eye on your plants, remove diseased material, and consider growing resistant varieties to keep your lettuce patch happy and healthy.
When and How to Harvest for Food Consumption
For head lettuce, grab a knife and cut at the base when it looks fully formed. If you’re growing looseleaf or baby lettuce, you can just snip what you need an inch or two above the soil line, and it will regrow like a tiny leafy phoenix.
Eating
Lettuce is mostly known for salads and sandwiches, but don’t stop there! Wilted lettuce is a thing (and it’s delicious), and grilled romaine will blow your mind. Or, for a fun twist, try making wilted "Crader Family Lettuce"—a traditional recipe submitted for the 2022 Seed Savers Exchange Conference.
Storing
Lettuce doesn’t last long, so eat it fresh! If you must store it, keep it in a plastic bag in the fridge for up to six days.
How to Save Lettuce Seeds
Life Cycle
Annual—lettuce likes to get things done in a single season.
Recommended Isolation Distance
Separate varieties by 10-20 feet unless you want some wild lettuce crossbreeds.
Recommended Population Sizes
For viable seeds, save from at least one plant. If you want to keep your variety strong over time, aim for 5-10 plants. If you’re feeling extra ambitious and want to preserve rare varieties, go big and save from 20 plants.
Assessing Seed Maturity
Lettuce doesn’t just go to seed—it bolts, shooting up a tall flower stalk like it’s trying to escape your garden. Once the plant starts looking more like a dandelion than a lettuce head, you know you’re on the right track. When fluffy gray pappuses appear, the seeds inside are fully developed and ready for harvesting.
Harvesting
Since lettuce seeds like to catch the wind and fly away, you’ll want to collect them before they make a run for it. You can handpick individual seed heads by grabbing the fluffy tops before they take off. Each tiny flower gives you about 15-25 seeds, so this is a great method if you just need a small batch.
For a more efficient approach, gently bend the plant into a bag and shake it like you’re making a lettuce maraca. Start when about a third of the seed heads are mature and repeat the process every week or two until you’ve gathered enough seeds.
Cleaning and Processing
If you’ve collected seeds by hand or shaken them into a bag, you won’t have too much chaff. To clean the seeds, rub them lightly between your hands or against a screen to separate them from the pappuses.
If you went all out and harvested entire plants, you can thresh them by shaking, rubbing, or even flailing the seed heads onto a tarp. Once you’ve got a pile of seeds and chaff, use screens or winnowing to separate the good stuff from the fluff.
Storage and Viability
Lettuce seeds, when stored properly (cool, dry, and in an airtight container), can last up to six years. But let’s be real—you’ll probably be growing more long before then because, let’s face it, lettuce is just too easy and too delicious to resist.