Vegetable Garden: How to Extend Your Lettuce Harvest

Why does lettuce bolt and how can I extend my lettuce harvest? Learn the answers to these questions and another leafy green to try out in the vegetable garden.

Do you enjoy eating lettuce straight from the vegetable garden?  If I had my way, I’d grow it all year long.  Unfortunately, lettuce is a cool-season crop and eventually ‘bolts’, making it inedible.

Romaine lettuce that has begun to bolt.

Romaine lettuce that has begun to bolt.

What does it mean when lettuce ‘bolts’?  ‘Bolting’ refers to the sudden burst of growth that lettuce undergoes as it suddenly grows taller and begins to flower and later set seed.  This usually happens toward the end of their life or in response to other environmental factors.

Seeds forming on bolted lettuce.

Seeds forming on bolted lettuce.

The first reason that lettuce bolts is in response to warm temperatures over 90 degrees.  Most leafy greens like lettuce are cool-season crops therefore warm temperatures signal the end of their growing season.

Secondly, the increasingly longer days in summer also have a role in leafy greens starting to bolt.  Again, they are a  cool season crop and when temperatures rise and the days begin to lengthen, it signals to them that it’s time to get busy sprouting flowers and seeds before dying.

spinach that has bolted

Spinach beginning to bolt.

Lettuce bolt as they near the end of their life, even when grown during cooler weather.  Warm temperatures and long days can hasten this process, but it will eventually occur without them.

Can you still eat lettuce or other leafy greens after it has bolted?  You won’t want too, because it tastes bitter.

Is there anything you can do to extend your lettuce harvest before it bolts? While all leaf lettuce will eventually bolt, you can select varieties of lettuce that have greater heat tolerance, which provide a few more weeks before lettuce bolts.  Various seed companies have a number of heat tolerant varieties of lettuce available.


Romaine lettuce going to seed.

Romaine lettuce going to seed.

Another way to extend your lettuce harvest is to plant successive crops.  In addition you can plant a crop of lettuce at the earliest point that the vegetable gardening calendar says you can for your area and then plant additional crops at 3 week intervals until you reach the end of the growing season for lettuce.

What should I do once my lettuce has bolted?  Resist the temptation to pull it out right away.  Allow it to flower, which attracts pollinators to your garden.  Then allow it to form seeds, which you can harvest and plant the next growing season. Note: seeds from heirloom varieties of lettuce will produce the exact same type of lettuce, but hybrid varieties won’t – they will be slightly different but you can still grow lettuce from them.

Once your lettuce has finished flowering and you’ve had the chance to collect the seed, then pull it out and throw it into the compost pile or let your chickens eat it – they love lettuce!

Malabar spinach

Malabar spinach

I love eating leaf lettuce from my vegetable garden and lament the fact that it won’t grow all year, which is why I am very excited about this new type of leafy green that can grow through the heat of summer.  Malabar spinach, while not a spinach,  it can be used in many of the same ways.  It tastes great in soups and casseroles.  Some people add it to salads where it adds an earthy flavor.

Easily grown from seed, Malabar spinach needs a small trellis to grow up on for best results.  It self seeds in many cases, coming back up the following year once temperatures warm up.  Many seed companies now offer Malabar spinach seeds.

With careful planning, you can extend your lettuce harvest by planting heat tolerant varieties, planting successive crops and once it bolts – add Malabar spinach for a long season of delicious greens straight from your vegetable garden.

  1. Judy says

    Thanks for the great information. I now have a better understanding of why my lettuce crop did what it did and how to work better with it next year.

  2. Lisa says

    I planted leaf lettuce the middle of May and it’s just now starting to bolt. We have had the best summer here in the Pacific Northwest, so I’m not sure why this has been growing so long. But it’s been great!

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