Grow a Quick Crop of Lettuce Indoors

| 1/19/2009 4:13:24 PM

Tags: growing lettuce, indoor gardening, small-space gardening, salad greens, lettuce,

LettuceBoxesBP If you itch to start growing things weeks before it's time to start most of your seedlings, use the space under lights (or your sunniest south-facing window) to grow quick crops of lettuce.

There is a happy symmetry to the fact that translucent clamshell boxes used to package gourmet salad greens also make ideal containers for growing lettuce indoors. To get the boxes ready for duty, use the tip of a stout knife to make 8 or 9 gashes in the bottom of each one. Then add 2 inches of moist potting soil before planting a pinch (about 25) lettuce seeds, barely covering them with soil. After generously spritzing the surface with water from a pump-spray bottle, pop on the tops and slip the boxes under your grow light, or in any warm, bright spot.

Five days later, when the seeds are up and growing, remove the tops and place them under the boxes, so they become watering trays. The soil usually stays nicely moist if you fill the trays with water every day. By the way, don't try to remove the labels from the lids. Hot water will warp them, especially if they're made from cornstarch.

You can let your boxes of lettuce bask in the sun from a south-facing window on bright days, but they will be happy to spend most of their time under the light. Keep the lights on for about 12 hours a day, like from 7 in the morning until 7 at night.

Cutting Lettuce BPThe first cutting is ready in 3 to 4 weeks. By holding the boxes sideways, you can clip the leaves right into a colander while keeping the growing crowns intact. The plants will be ready to cut again in about 2 weeks.

If you want to use the clamshell boxes to start another crop, you can lift out the mat of seedlings and transplant it to a larger container. As days get warmer in the spring, you can start lettuce and other salad greens in clamshell boxes and transplant the mats into a cold frame or plastic-covered tunnel. 

Paul Dyson
10/5/2012 9:14:05 PM

I have totaly give up on growing outside this year as summers are getting rubbish and the season seem all out of tune these days, not forgetting kids raiding the garden and slugs and snails makes outdoors not as viable as it once was.

Paul Dyson
10/5/2012 9:08:14 PM

What I am going to try do is use the loft space to grow salad stuff toms etc going to try leds and fish tank tubes red and blue, its just space for junk at the moment. foods getting more pricey and benifits are getting cut to the bone.I also think growing mushrooms under the downstairs flooring in the house would be a good idea.

Cathryn Lee
4/6/2012 2:04:43 AM

I have been having fun growing food plants in my south facing window. The most successful have been basil, dill, lettuce, string beans and cucumbers. I had 2 full size cukes off of my first plant so far. I use lots of different containers - regular pots, painted mason jars, and large food service cans. I use potting soil mixed with my compost from outdoors. I use the water from a 10 gallon fishtank with about 22 goldfish in it. That feeds/waters the plants. I am going to get a bigger bucket for the corner of my front room and try to get some zucchini going. It bugs me to buy it, so I will give it a try.

Wendy Bacon
2/4/2012 4:17:55 PM

I saw on channel 2 wgrz tv you can do the same thing except using just wet paper towels instead of soil. im going to try it.

Outdoor Lighting
4/16/2011 3:50:15 AM

Hi,This is very nice blog .i like it very much. I think grow the crops in indoor Has a great idea.Thanks for sharing a wonderful article......

2/14/2011 9:00:00 AM

If you do any type og gardening only use heirloom seeds. ---------------------- Buck Http://www.seed heirloom seeds "How God plants His garden"

3/8/2009 9:46:39 PM

Hi, I'm a bigginner in building an indoor garden, not much success though. Would like to learn some tips on how to prevent bringing bugs/insects indoor when the garden is indoor. How to prevent molds on dirts and plants (I leave in Malaysia - tropical/humid weather all year round).

3/2/2009 6:56:50 PM

For those of you wanting to start your plants outdoors, in enclosed containers, place a black painted brick in with your seeds. This brick acts as a heat grabber and will keep your seeds warm well into the evening

3/2/2009 3:09:56 PM

curtisjon- I tried to grow lettuce as well and it started off well. When I replanted, they were not very strong, they turned yellow, and now are wilting. I started in peat pellets and did not take the net off. Maybe that was the problem. I have cilantro ready to replant and I am scared.

3/2/2009 12:27:30 PM

Thanks for your comment, Richard! You are right. Sprouts are cheap and easy to grow. And fun! Learn more about growing sprouts in "Kitchen Counter Gardening: Try Sprouts": -Tabitha Alterman, Mother Earth News

Richard Schwab
3/1/2009 10:40:14 PM

I have found that the easiest thing by far to grow indoors is sprouts. You don't need dirt, they can be harvested in days, you can get a wonderful variety of flavors, and you don't even need a light or window. And, they're some of the healthiest foods you can eat. Oh, and their soooooo cheap!

3/1/2009 6:36:02 PM

oops, not 2" - " = inch, but 2' - ' = foot, so 2 foot or 24"

3/1/2009 5:54:56 PM

I just bought at Lowe's 1 mini greenhouse - $34 2 aquarium/plant flourescent bulb 2" $9 each 1 dual 2" florescent shop light fixture - $16 I had the plug and cord from an old lamp at home. You should know a little about electricity to do it this way. If you are at all unsure about your ability to wire up the light safely (as in you have done it before with someone who knows what they are doing to inspect the work) jsut buy a fixture that has a cord attached for a little more money. I'll add another light to this in another month. I have herbs, catnip, some peppers, garlic to go out in the outside garden in a few weeks, and I started some mescalun mix.

3/1/2009 5:52:54 PM

I started some lettuce in small peat pots. They came up well but face a East window. They are slender and fall over. Is it because of lack of sun or anything else? Thanks, Curtisjon

Robert Bakhaus
2/28/2009 9:25:16 PM

Gentlepeople: Since I'm new here in the Appalachian mountains I've been experimenting with growing "crops" indoors in the winter - my cheapo approach to greenhousing. I've had some success, and some failures. I've even started regarding my potato crop as my "pets" because of the tricks I can "teach" them of turning this way or that in response to lighting changes as I rotate their pots by the windows. This trick works best with young plants that have less plant mass to move. I'd love to hear more about other folks success with indoor wintertime gardening.

2/28/2009 7:23:54 PM

Can you take a "crop" out of the clamshell and put it into a container for container gardening? Thanks, Sharon

2/28/2009 7:21:47 PM

so, when using the clamshells to start lettuce (and other plants),can I transplant them right into containers? (I do container gardening in my yard but have never started from seed). Any help would be appreciated. Thanks, Sharon

2/28/2009 2:35:25 PM

My apartment faces a mini-forest, so there's no direct sun - full shade! What 'light' do you suggest for growing lettuce indoors? And how far away/high above the clamshell should the light be? Would love to be able to grow herbs as well. Thanks!

Amber Cain
2/27/2009 6:40:03 PM

This also works great for arugala during the summer here in florida!

Mary Burch
2/27/2009 4:16:39 PM

I have always used the clamshells as mini greenhouses. Right now I have tomatoes, cucumbers, fennel, chard and stevia growing in my window. We have very hot summers and growing lettuce just isn't an option. So I will try this in the summer when lettuce would bolt in the garden.

2/27/2009 1:16:08 PM

By the way, we created a 20% discount for Mother Earth readers. Just enter the Discount Code MOTHEREARTH during checkout. Enjoy!

2/27/2009 1:13:22 PM

Wow! It's great to see a satisfied customer! I'm the co-owner of Surf City Growers (, creator of My First Organics, and I recommend Butter Lettuce as a great starter and crop for both container and garden plot plantings.

Amy H.
2/27/2009 10:35:25 AM

Love this idea! We have a small indoor "garden" growing on an office window sill. We set up a My First Organics seed starting kit. It was quick and easy to get going, and we all enjoy watching the plants grow. It's amazing how fast they've taken off! (

2/27/2009 7:57:36 AM

Any suggestions on specific types of lettuce?

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