Turn 1 Lettuce Plant into 100 Lettuce Plants for Free

A lettuce plant's time in your garden is brief. Sometimes too brief. It can be upsetting when you notice your lettuce plants are beginning to bolt (or go to seed) and the flavor of your leaves starts changing. Mourn the loss of your fresh, homegrown salads, but keep in mind that you're about to get something else: lettuce seeds!

Seed formation is a natural progression in the short life cycle of a lettuce plant. It's a gentle reminder that our plants have a purpose far beyond what we're growing them for, and that purpose is to make more of themselves for the future. Instead of ripping up our lettuce plants once they're no longer giving us tasty leaves, we can roll with it and let them go to seed. Once those seeds form, we can collect them and save them. Assuming the lettuce plant wasn't a hybrid, the seeds will remain true to the original plant.

That's how we end up with hundreds of seeds from just one lettuce plant. Free seeds for your next cool season!

Let's look at how to save your own lettuce seeds.

When Do Lettuce Plants Go to Seed?

Lettuce plants typically go to seed due to stress when the weather grows a little too warm for their liking. Lettuces love nice, cool weather (think spring and fall in most places or even winter in warmer climates). They don't like when the temperatures rise above 80°F. They're also sensitive to day length, so the increasing hours of sunlight we enjoy as spring moves into summer is sometimes enough to tell your lettuce plants their time in your garden is coming to an end.

When plants feel stressed, they could put more energy toward their own survival. But what most short-lived plants do instead is focus all their energy on producing seeds. This is their way of looking toward the survival of their kind. Seeds ensure that copies of the lettuce plant will exist after it dies.

3 Signs Your Lettuce Plants Are Going to Seed

Once you notice these three signs of going to seed, your lettuce leaves will likely begin to have a bitter taste and a more rubbery texture.

Sign Number 1

Your lettuce plants will send up a tall central stalk. These stalks can eventually grow several feet tall.

Sign Number 2

Your lettuce plant will begin forming flowers, pretty little yellow florets. Each floret will eventually contain the seeds.

Sign Number 3

The base of your lettuce plant may begin producing a white sap. This is especially common in romaine lettuce plants. This sticky, milk-like substance is actually a natural form of latex called lactucarium (lactus means milk in Latin). It's this sap that's causing the flavor and texture of your lettuce leaves to change. The sap itself is 100 percent edible, but most people don't enjoy the bitter taste.

Step One: Pick Your Favorite Lettuce Plants

It's best to only save seeds from your favorite plants. Maybe this plant looked particularly beautiful or healthy or tasted extra delicious in your salad bowl.

I don't recommend picking those plants that were the first to bolt. We only want to save seeds for desirable qualities. Over time, you can actually select for plants that are better and better adapted to the particular growing conditions in your garden space, which is pretty cool.

Go ahead and remove the plants that you won't be saving seeds from. That way, you'll free up some space in your garden for plants that are happier to grow during your current season. The best way to remove these plants is by cutting them right at the base instead of yanking them up, roots and all. You can compost these plants as long as they're not showing signs of pests or disease.

Step Two: Protect the Flower Heads as They Form

You'll need to leave your favorite lettuce plants in your garden while they go to seed. You'll no longer be harvesting leaves from them, but you'll soon be able to admire the dozens of pretty lettuce flowers they produce. These flowers attract pollinators to your garden right around the time your fruiting plants need pollination.

Lettuce flowers form from top to bottom on the plant. Most of these little florets will self pollinate (meaning you don't need insects to come visiting), but it is possible for them to cross pollinate if you have a bunch of different lettuce varieties growing close together and flowering at the same time. If you're concerned about cross pollination, just place a small mesh bag (you know, like those little organza bags you might store jewelry in) around the seed head. This will keep pollinators out, and it also helps collect any seeds that might fall and be carried away by the wind.

Your plants will also need to be staked or placed inside an obelisk trellis now that they've grown so tall to prevent them from falling over.

Step Three: Collect the Seeds

Lettuce seeds are ready for harvest about 2 to 4 weeks after the flowers have formed. As soon as your flower heads begin drying up, cut the entire lettuce plant at its base, right at the soil level, using a clean pair of pruners. Tie a piece of twine around the stem and hang the plant upside down in a cool, dry place for a couple of days. The seeds will need to be completely dried out before you collect them or they could mildew. You'll know they're dry when they're nice and loose and ready to fall off.

Shake the bolted lettuce plant over a bucket or tarp to collect the little brown seeds. Use your fingers to rub free any stubborn seeds. Before storing the seeds, pick through and remove the chaff (the debris from the dead plant).

Each little lettuce floret can contain up to 25 seeds, so you should be looking at a pretty large supply of lettuce seeds for next year.

How to Store Lettuce Seeds Saved from Your Garden

Store your collected lettuce seeds in a paper sack, a jar, or an envelope. Be sure to label with the date collected and the type of lettuce seed. Your seeds can potentially last up to five years if you store them properly (in other words, protect them from heat, direct sunlight, and moisture to prevent mold and premature sprouting).

How I Inadvertently Grew the World's Tallest Lettuce Plant While Waiting on Seeds to Form

My favorite salad mix is called Rocky Top lettuce mix, from Baker Creek Seeds. It's similar to a spring mix you'd buy from the grocery store (but way tastier, of course), so it's got romaine, red lettuce, butter crunch, and then some rare heirloom seeds.

Lucy, the world's tallest lettuce plant, grew from this seed mix and was clearly an heirloom lettuce. (Yes, I did name her.)

I planted seeds from this mix at the end of February, and just two months later, the resulting plants started to bolt. I removed Lucy's friends from the garden, but Lucy herself was just looking too beautiful to cut. Sure, she was bolting and growing taller, but she didn't appear scraggly or out of control. She still looked like she was living her best life, so I left her to stand tall in all her bolting glory.

After about three more weeks, I had to add a trellis meant for cucumbers near Lucy to give her some support because she was growing top-heavy from her abnormally large seed head. She was 47" tall at that point—just shy of being 4' tall! For comparison, most lettuce plants only grow between 2' to 3' tall in their lifespan.

I kept hesitating to remove her because she would have brown seeds ready to harvest but also new green buds and flowers. "If I wait a little longer," I thought each day, "I'll get more seeds."

By the time I removed Lucy in mid September, she stood at a whopping 5’6’’. I considered submitting her to the Guinness Book of World Records as the tallest lettuce plant in the world. And at almost 7 months old, perhaps the oldest, too.

I was sad to see her go when I finally cut her down and harvested her seeds, but you know what? A bunch of little Lucys started growing from seeds that had fallen from her seed head the very next cool season. And because I saved seeds from her, Lucy can show her majestic self in my garden for years to come.

If you'd like to try to grow your own Lucy, look for heirloom variety seeds. They'll have unique components that allow them to grow in ways your typical garden-variety salad plants won't.

Time to Save Your Own Lettuce Seeds

Seed saving is the garden's version of making lemonade when life gives you lemons. You're no longer going to harvest delicious leaves from the plants. Instead, you're going to get seeds, and seeds are little promises for harvests to come. It's incredible to think that a plant that grew from a tiny seed has now produced hundreds more of itself.

There’s so much magic growing right outside your back door. We often feel like we have to go somewhere cool or buy something new to bring joy into our lives, but honestly, it just might be waiting inside a little packet of seeds. You never know when one seed you plant is going to turn into your own Lucy or something else new and exciting.

So, experiment with growing different types of lettuce seeds and when you notice them bolt, let some of them stay in the garden and watch them do their thing.

You never know.

Thanks for bringing back the kitchen garden with me one bolting lettuce plant at a time!