Grow lettuce in grow bags (or other leafy greens)

Here in this article I will give you 3 great reasons why you too should grow lettuce in grow bags. I will also show you how to make your own DIY grow bags for growing lettuce and other shallow root vegetables at home.

You can of course opt to buy readymade grow bags. But truth to be told, it is not difficult to make your own grow bags for growing lettuce at home. A bit fiddly? Yes. Especially if you are not used to sewing machines.

But after making that one first grow bag yourself, you will realise 3 things

  1. Threading the needle was the hardest part in making your own grow bag
  2. It doesn’t matter if seams are not perfectly straight or centred – the grow bag will still look great and – even more importantly – work as intended
  3. Having (access to) a sewing machine makes all the difference
We make DIY grow bags for many of our herbs and vegetables including cherry tomatoes, beefsteak tomatoes and different varieties of peppers and chillies including cayenne pepper, habanero peppers, ghost peppers and Spanish Padron peppers.

How to make grow bags at home

Watch our instructional video on how to make grow bags for growing lettuce and other leafy greens below.

Watch this video on YouTube.

How to grow lettuce in grow bags

1. Fill the grow bag with soil: lettuce likes a loosely structured, well draining, compost-rich soil. There is no need to add fertilisers at this stage. If your soil is not up to par, spend some time improving the quality of your soil.

2. Make lines in soil with a finger or using a dibble: Draw lines in the soil aiming for a depth of 1 cm / ⅓ inch. Allow for at least 10 cm / 4 inches between rows

3. Premoisten soil: Lettuce seeds are very small and can easily be displaced when you water. Instead you should premoisten your soil before you plant your seeds. 

4. Plant seeds: space seeds approximately 3 cm / 1 inch apart and cover with soil. Seeds will germinate in days rather than weeks and you can always thin your baby lettuce seedlings should all seeds germinate.

5. Keep moist and temperate: Do not let your lettuce dry out. Keep soil moist and place the grow bag in a location with good light that is not too hot. Lettuce does not like temperatures of 20 degrees Celsius / 68 degrees Fahrenheit and above. 

Why we use grow bags to grow lettuce 

Grow bags are extremely versatile and can be used to grow most herbs and vegetables. And grow bags are definitely one of the better ways to grow lettuce and leafy greens like arugula (rocket), corn salad, spinach and kale.

Most lettuces grow fast and it typically takes 3-4 weeks from starting lettuce from seed to harvest during the ideal growing season. And this makes lettuce an easy to grow vegetable for spring and summer.

But we like to grow lettuce and leafy greens year round. And ideally we like to be self-sufficient for the largest possible part of the year. For us this means a combination of several different growing methods during the year. 

  • hydroponic grow beds are ideal for growing lettuce, arugula and spinach in winter 
  • starting seeds and growing leafy greens in soil bags works great during spring and summer when the temperature stays above 10 Celsius / 50 Fahrenheit
  • Shallow home made grow bags for early spring and late fall planting

And grow bags have been great for us during these shoulder seasons when the outdoors is still not quite warm enough but there is enough natural light in greenhouses, conservatories and even window sills.

3 (more) great reasons to grow leafy greens in grow bags

I am not saying that grow bags are the cheapest or even best way to grow lettuce.

Cheapest is of course to use a container you already have at home. And as for “best”, it will always come down to personal opinions and preferences. 

But I will argue that grow bags are a great alternative as they are durable, reusable and work great for growing herbs and vegetables. 

Here are my top 3 reasons why grow bags are great for growing lettuce and leafy greens.

1. Easy to use and store

When you know how to make your own grow bags you will find that grow bags are the Swiss Army knives of pots and containers.

As you can see from our videos it is easy to alter the dimensions and make the grow bags fit your purpose.

And this makes all the difference when you grow lettuce and other leafy greens. 

Make your grow bags large but shallow to maximise your growing area. But do not get greedy. Always remember that grow bags should be portable. 

We make our grow bags for lettuce 50 cm x 35 cm with a depth of about 12 cm. This size grow bag has a large enough grow bed but is at the same time easy to move and handle. Also, we do not have to spend money on filling a deep grow bag with potting soil unnecessarily. 

2. Promote healthy root systems

You need to give your herbs and vegetables a good growing environment for the plants to grow and develop. 

And for vegetables like lettuce and other leafy greens this means using shallow grow beds where roots can grow strong in a moist but not wet growing environment.

And even though this is easy to understand, I find that garden enthusiasts have a tendency to overwater lettuce while using a faulty one-container-fits all approach.

Let me explain what I mean.

Lettuce develops a shallow root system and needs frequent and shallow watering. Shallow watering as the roots stay shallow.

But if you plant lettuce in a 5 gallon container you will have to water a lot to keep the surface of the soil moist. 

The water will trickle down to the bottom of the container. And when the top of the soil dries out the soil at the bottom of the container will still be wet.

Now you are watering an already wet soil and this can lead to problems with diseases and pests.

The solution is to use shallow grow bags made from a material that breathes.

You will have to water a lot less as the shallow grow bag holds less soil. Also, as the material breathes there is much less risk that water sits stagnant and unused in your grow bag. 

3. Easy to make and will save you money

It is not difficult to make grow bags and it will save you money when you sew grow bags at home. Given that I have a sewing machine the cost breaks down as follows.

To make grow bags I need breathable landscape fabric, durable outdoor thread, pins and a pair of scissors. 

The fabric I buy will make 10 medium sized (1 square foot) grow bags.

The thread, pins and scissors will be used for many more than the initial 10 grow bags.

This gives me a per grow bag cost of:

For the initial 10 grow bags:  EUR 2,20 / USD 2.50 per grow bag
For grow bag number 11: EUR 0,90 / USD 1 per grow bag

It is hard to beat this cost and also remember that you will have success when you grow lettuce in grow bags.

Are there any disadvantages to using grow bags?

I cannot see any disadvantages to growing lettuce in grow bags. There may be options that are (almost) as good – but, as far as I am concerned, grow bags will win when you take cost into account.

There is however one factor that could be seen as a disadvantage. As the material of grow bags breathe, you would need to water more often compared to growing herbs or vegetables in a plastic or composite container.

I would argue that this is a “feature and not a bug” as it helps promote healthier roots systems.

Still, I guess it could also be seen as a disadvantage.

3 common mistakes growing lettuce

Lettuce is a great beginner vegetable as it germinates in days and can be ready to harvest in just a couple of weeks.

Still, to get a really good harvest, you should avoid making these common mistakes.

1. Planting seeds too densely: Lettuce needs room to grow and develop and fresh lettuce seeds tend to have a high germination rate. Planting seeds too densely will result in a large number of small plants blocking each other from developing into healthy plants.

2. Choosing a location that is too hot: Lettuce does not do well in hot temperature of 20 degrees Celsius / 68 degrees Fahrenheit and above. Hot temperatures will stress the plant to bolt into bloom effectively ending the season for the plant from a harvesting perspective. 

3. Letting your lettuce dry out: It is important to keep the soil moist when you grow lettuce in grow bags. Drought can kill your plants but also give the leaves a bitter after harvest. Moist solid and continuous watering will give you good harvests of healthy and crispy leaves.

Meet the author: Mattias is an experienced gardener spending most of his free time on his knees among herbs, plants and garden vegetables. For the past two years he has been sharing gardening projects and how-to tutorials on the NordicLavender website and YouTube channel.