How to Grow Lettuce and Herbs Indoors

It’s the end of January and I am eagerly anticipating the start of the busy gardening months, but it is still just a bit too soon to plant outside. I’m already craving fresh salad greens from the garden, but the frost twinkling on the garden beds in the morning sun reminds me that that pleasure is still some weeks away, so I figured why not bring the garden inside! Did you know you can grow lettuce and herbs indoors? You can! Today’s post will show you how.

You’ll need a few things for this project, including:

• containers to grow your greens, ideally 6″ deep
• growing medium (potting soil or a seed starting and compost mix)
• seeds
• grow light or a sunny windowsill

I have this tabletop LED grow light that I am using for this project. It technically can be done on a windowsill, but the seedlings tend to get leggy.

You can be creative when it comes to the containers you use here. Lettuce has shallow roots but still needs adequate space to grow well, so a container with drainage holes at least 6″ deep is best. I used 1-gallon plastic pots, but I’ve used those plastic salad containers from the grocery store successfully in the past! Other ideas include yogurt containers, giant Costco hummus containers, milk gallons with the tops cut off, etc. Whatever container you use, make sure there are drainage holes.

I recommend planting your containers outside as soil can quickly get everywhere. Outside we go!

Step 1: Prepare your growing medium.

The growing medium is up to you. You can use a general potting soil, or use half seed starting mix, half compost like I did here. I find it is easier to mix the compost and seed starting mix in a separate container rather than trying to mix them in the individual pots. I filled half of the container with compost and the other half with seed starting mix, then I used my hands to mix the two up.

Next, I used my handy dandy watering can (duck) to moisten the soil mix. I didn’t measure an exact amount of water here, I just mixed it until everything felt moistened and when I squeezed it, the soil stayed compressed in a ball, but wasn’t dripping wet.

Step 2: Fill your planting containers.

Once I got the soil mix moistened, I filled the containers. And made a mess. Again, I really recommend doing this outside.

Step 3: Plant the seeds!

Next, I planted the seeds. All of these seeds came from Baker Creek. The back of the seed packets have seed spacing recommendations, but I like to densely sow the seeds for baby greens. If you wanted to grow full heads of lettuce, you’d need to give them more space and only plant 2-3 seeds per container. I’ll be harvesting at the baby leaf stage so I can sow densely.

In two of the containers I scattered the rocky top lettuce blend seeds over top the soil. I seeded heavily. In another two, I planted the sanguine ameliore (strawberry lettuce) seeds by placing 2-3 seeds in 4 holes evenly spaced around the container. I planted the herb seeds in the remaining two containers. I scattered cilantro on top of the soil in one and in the other I densely seeded the basil.

Step 4: Lightly cover the seeds with growing medium and mist with water.

I covered all the seeds with a thin layer of seed starting mix and misted the top with some water. Because the soil was pre-moistened, the containers only needed a light misting with water.

Step 5: Place under grow lights (or on a sunny windowsill).

Some seeds need light to germinate while others don’t. Lettuce seeds do, which is why I covered them with a thin layer of seed starting mix and placed them under lights right away. I raised the grow lights so they would be about 2-3″ above the containers. You want the grow lights close to the containers to prevent the seedlings from becoming too leggy as they stretch for the light.

Step 6: Eagerly await for germination!

Over the next few days, I turned the lights on when I came down for coffee in the morning, and turned them off before going up to bed at night. The lights were on about 12-15 hours per day. I started to see little sprouts appear about 3 days after placing them under lights.

I misted the soil after a few days to prevent it from drying out. If the medium turns a light brown and looks a bit dry, give it a drink. These lettuce and herbs like regular moisture but don’t want to be waterlogged.

Here’s what the containers looked like 15 days after planting:

Yay happy lettuce greens and herbs! Once the lettuce plants had two sets of leaves (around 17 days after planting), I fertilized them with diluted liquid fertilizer containing an emulsion of fish and seaweed.

These containers are looking great so far. I will continue to monitor them and give them water if the soil looks dry. Stay tuned for an update on the indoor lettuce and herbs in a few weeks!

Looking for more indoor growing projects while you wait? How about growing your own pea shoots? They are a delicious addition to salad, sandwiches, stir-frys, and soup!