Lettuce can be grown indoors. It’s one of the easiest plants to grow indoors or out. Managed properly, lettuce can be grown all year round for most salad dishes. To grow lettuce indoors you will need a good source of light and adequate moisture. Artificial light is usually needed to grow lettuce indoors.
You can grow lettuce indoors in a sunny window
Sunlight may be enough. Look around your house to find a position where plenty of daylight is coming in. Lettuce needs 12 hours of sunlight every day. This is a tall order. It would be unusual to get 12 hour of sunlight every day when growing lettuce outside let alone indoors.
If you have a South facing bay-window, this would be ideal for growing lettuce. If getting enough light becomes a problem; for most of us it is, artificial light will be the answer. There are indoor gardening units that have pronounced lighting features that will ensure that lettuces have a constant supply of light. Find out more about LED indoor gardens and grow-farms.
A shallow container with drainage, for lettuces
You could also use a multi- pot arrangement or food-product containers rather than throw them away. If it can hold potting-soil you can grow lettuces in it. Stretch some cling film over the top and you have a propagator for germinating and starting lettuces.
Lettuces can be grown from seeds or you can buy lettuce plants at many nurseries. You will need a container that has drainage in the bottom. This must be filled with a suitable seed-potting mix. Make holes in the seeding medium with a finger, 4 to 5 inches apart.
Drop a couple of seeds in each hole then cover them. Keep the soil moist but not saturated and you should see lettuce shoots appear after a few days.
Can lettuce be grown indoors? Yes. Regular fresh salad greens!
Lettuces grown indoors need attention
Seedling lettuces need to be green and sturdy. If they’re tall and leggy with a yellowish appearance, this indicates poor light levels. It could also mean that the lettuce plants are being over watered.
When you see signs of the first main leaves on the lettuce seedling you can introduce some liquid fertilizer. Maintain a moisture level that doesn’t reach saturation.
After about 4 weeks you should have small lettuces which you can start harvesting from. Lettuce leaves need to be consumed soon after they’ve been cut. They will become limp if stored for long.
Lettuce leaves can be taken from the outside of the growing plant. This will leave the inner part of the plant to carry on growing from the middle outwards.
The best part about growing lettuce and salad greens indoors is that you can keep the slugs under control by either constantly monitoring them or by placing slug pellets around on the soil surface. You won’t need to use very many.
Which lettuce should I grow indoors?
There are many varieties of lettuce. Some of them are more suited to being grown indoors than others. The best lettuce varieties for growing indoors are the loose-leaf types. These will include Tom Thumb, Black-seeded Simpson and Baby Oak-leaf. Loose-leaf lettuce plants are easier to manage when you come to extract the outer leaves as they mature.
There are other lettuce varieties that appear to grow where there’s less light. These include Winter Density, Winter Marvel and Arctic King.
Regrow lettuce from a stump
Some success is possible from regrowing lettuce from a stump of a store bought lettuce or a lettuce that you have grown and harvested. The best variety for doing this appears to be ‘romaine’. If you are planning on growing lettuce by this method you can start by cutting off enough of a stump from the original plant. The stump needs to be at least an inch high to have a good chance of generating lettuce leaves.
This method involves sitting the lettuce stump in water. The lettuce leaves that this will generate won’t be as big as those on a fully grown lettuce plant that’s been grown from a seed or seedling.
If you can get this to work you should be able to take lettuce leaves after about 14 days. This is the point where the lettuce leaves will have reached their maximum size by this method. They may not be as big as full lettuce leaves but they make fresh salad greens that can be added to any salad.
Things you will need:
- The lettuce stump – this can be taken from a mature lettuce that you’ve removed the main leaves from, for a salad. When you try this method, allow a big enough stump that can provide a good base that has potential for re growth. Some say that you can cut away the base of the stump to encourage fresh root-growth. In practice you will find that a lettuce stump will develop roots from the original harvesting-cut. Where the original cut has happened, it may not leave enough material to cut away, so, it’s usually better to leave it as it is.
- The container – this can be a simple plastic container but you can use glass. It doesn’t need to be deep. A lettuce stump can produce roots and begin growth in just an inch of water. Don’t allow the stump to be immersed too deep in the water as this can lead to rotting. The cut-off part of the lettuce stump only needs to be just touching the water surface.
- The water – you can use tap water. This must be changed every two or three days to prevent it from going stagnant.
Lettuce can be grown using this method by relying on light coming through a window, preferably South facing.
Cutting fresh lettuce leaves
If all goes well you can expect to see lettuce leaves grow to a height of 4 to 6 inches. It will depend on which variety of lettuce you’re attempting to grow but the usual method of harvesting is to take the outer leaves from whatever has grown.
Lettuce grown indoors using the regrow in shallow water method can provide a regular supply of fresh salad greens all year round.
There will come a time when the lettuce stump will cease to be productive. You can achieve continuity by setting up a number of lettuce stumps. These will be producing lettuce leaves all having grown at different stages.
The modern way of growing lettuce indoors
The best way to grow lettuce indoors is to use a specially designed indoor garden. These are set up to provide everything a lettuce plant needs from seed to harvest.
The biggest problem that most people have when they attempt to grow lettuce indoors is providing enough light. When we grow anything indoors we are always compromised by the light issue.
The specially designed indoor gardens comprehensively counter this problem by including a bank of lights that maintain a thorough illumination for as many hours in a day as lettuce plants need.
This is the modern way of growing lettuce indoors. There’s no soil involved. The roots of the lettuce plants are encouraged to grow down into a nutrient-rich solution. This is a highly efficient way of growing any plants indoors, not just lettuces.
You can find out more about growing lettuce and other plants indoors using indoor gardens or Grow-farms.
How to make a shop-bought lettuce last longer
This is something that I do from time to time. It’s what I do with Iceberg lettuces if I want to keep them fresh and it can do so for up to three weeks, possibly longer.
I used to put lettuces in the refrigerator but it never seemed to work very well, then I read somewhere about sitting a whole lettuce in water so that it would stay alive and keep growing.
Very often an Iceberg lettuce will be supplied in a sealed plastic wrapper. This needs to come off to allow the lettuce to breath. You then need to place the lettuce in a shallow container of water in a way that keeps the lettuce upright.
Don’t allow the lettuce to be immersed too deeply into the water as this will lead to rotting. Just position the lettuce so that the base of the stump is just touching the surface of the water. It’s worth spending some time on this and checking that the lettuce isn’t in too deep.
Then you leave it for a few days and inspect it. Pick up the lettuce and take a look at the stump. You should see the beginnings of white roots emerging from the base of the lettuce stump. This is a good sign. It means that the lettuce is healthy and that it has a good chance of staying fresh this way for, possibly, up to three weeks.
You need to inspect the lettuce regularly, every couple of days, and change the water to keep it fresh. When you come to use the lettuce, you should be able to just peel off the outer leaves and the rest of it can go in a salad. You may need to trim off bits of leaves on the outside edges but the amount of waste should be minimal.
Enjoy your lettuce!