Growing Lettuce Indoors: A Step by Step Guide For Fresh Food Year Round

Growing lettuce indoors is not as complicated as you might think, especially using a hydroponic system.

When using soil, it can be difficult because of the need for frequent watering, sunlight and consistent weather but with irrigation and lighting systems setup inside, growing lettuce indoors becomes quite simple.

To do ths will involve a hydroponic system which is what I will show you how to build in these simple steps below

Growing lettuce indoors is easy and you will be amazed with the results in such a short amount of time (Lettuce grown indoors using a hydroponic system takes around 35 days).

This can be done by anyone. It only takes good planning and preparation and this article will give you that information so you can have fresh organic food, all year round!

Let’s dive in

1. What is hydroponics

hydroponics is a method of growing plants without soil (in water). by doing this we will be able to grow plants inside the house year round no matter what the weather outside is like. Growing lettuce indoors hydroponically has become very popular within the last couple of years because of the fact that people can now eat fresh food grown indoors all year long.

The benefits of growing lettuce indoors hydroponically are:

– Growing lettuce indoors hydroponically gives you a continuous fresh supply of lettuce throughout the year. (you will always have salad ready to eat).

– Growing lettuce indoors hydroponically is really easy. If you can water plants and flip a switch you are well on your way to growing perfect produce for yourself or even sell it

2. Why use a hydroponic system for growing lettuce indoors

Growing lettuce outdoors is relatively easy compared to other vegetables. The trouble is, Growing outdoors can make them susceptible to pests such as aphids or fungal diseases. Growing plants in pots outside also makes them vulnerable because they can easily dry out from wind and sun, which are two things that growing plants need to be healthy while growing.

Seasons are another big factor which needs to be considered. As with nature, there is only limited sunlight and warmth available during the colder months of the year which can make it difficult to have any vegetables growing outdoors.

Growing lettuce indoors hydroponically can be done on any budget and the cost of nutrients for your plants are under $5 per month which will allow you to grow more produce than you will know what to do with… ALL YEAR ROUND

3. How to build your own hydroponic system for lettuce

There are a few basic steps you need to take when building a hydroponic system for growing lettuce indoors, lets run through them below:

Growing trays

The first thing you will need to do is decide on how many plants or trays you are going to grow. Growing one plant per tray is the easiest way for a beginner to start off with, but if you want more lettuce quickly then 4-8 plants per tray is optimal.

You’re going to need to get the right kind of tray, which is made of plastic. The best thing to buy here is a large storage container

For me, I was able to find them at the local hardware store and they were relatively cheap. If you can’t find the right size at home depot or in general then all you have to do is build your own. All you need is a good quality saw and some type of watertight container. (you could use an old plastic bin).

Below is a picture of the bin I got from amazon, cut a few holes in the top and you’re good to go!

It’s that easy, and now you have a tray for growing

Water Reservoir

the next thing you will need is a reservoir for the water and nutrients to sit in while it’s being pumped to your plants. I recommend getting a reservoir that holds at least 2 gallons of water and is taller than most plants. ( 8 inches or more) this will give you more real estate space to put multiple plants on top of each other without them growing into one another.

If you went with the storage container option above then this will host as your growing tray AND water reservoir all-in-one

you can also use a bucket, but I would recommend using a big 5 gallon pail like this to hold your water and nutrients.

Seedling Support: Net Cup’s

net-cups are small plastic devices used to support your growing medium & seedling inside the reservoir, just above the waterline. you need one of these for each plant you want to grow. In order to use them, simply cut a circular hole in the growing tray, drop in one of these net cups and your ready for the next step.

Growing Media: What’s the best Growing Medium for lettuce? 

Growing media is one of the most confusing parts of creating your own Hydroponic system as there are so many you can choose from. It is the material in which you are going to grow your plants on top of and put them into, either from seed or as a pre-grown seedling

There are several types of growing medium that are suited for growing plants hydroponically. Growing mediums that include coconut coir, rockwool, perlite, or clay pellets can be a great start to building your own system.

For this example, and what i use at home, we are going to use rockwool like this.

Lighting: How to grow lettuce indoors even faster

This step is optional as natural sunlight coming through the window can work but, if you really want to have fresh, crispy lettuce all year round which grows bigger and faster then lighting is really going to help.

There are several options:

Florescent Bulb

One option to consider is using a florescent tube like this one that runs on only 10 watts, this way you can grow multiple plants very easily. the benefits of growing with florescent bulbs are that they use very little electricity and run cool which is important for your plants health.

LED Growing Lights

Another option for growing lettuce indoors hydroponically even faster is with LED Growing Lights these lights really help to cut down on the amount of energy used or wasted and are more powerful than florescent bulbs. the downside of led grow lights is that they are typically more expensive, although that is changing at rapid pace

So what kind of lighting works best for Growing Lettuce Indoors?

A florescent light will do the trick and they’re relatively cheap as well for the amount that you can grow with one light, but if you have the money then i would suggest looking into getting a led light.

Nutrients: What should I use for growing lettuce hydroponically

Hydroponic nutrients are the substances found in fertilizers that your plants use to grow. They provide all of the minerals, vitamins, and trace elements that your plants need to grow strong and healthy. Think of it as ‘plant food’, the same as humans need to eat a balanced diet not just water

Normally you should follow a hydroponic nutrient chart such as this when selecting the right type of fertilizer for growing lettuce indoors hydroponically:

How much Fertilizer should I use for hydroponic lettuce?

For lettuce you want to use around 5-10ppm (Parts per million) which is about 1-2 tsp per gallon of water. You wouldn’t want to overdo it with too much fertilizer because it would burn the roots and suffocate them.

In order to grow lettuce indoors successfully, i would recommend starting with a nutrient ratio of 15-30-15 (NPK). I typically use Miracle Gro All Purpose plant food and i have seen good results with this product as well as others.

All you need to do is add some of this to the water in your reservoir

4. Steps on how to grow lettuce using the hydroponic system

Getting Started: Growing Lettuce from seed

Alright so now it’s time to get your hands dirty and start growing your own lettuce indoors hydroponically. The first thing you’re going to need to do is get some seeds

There are several types of seed you can choose from, which i will break down in another post. Seeds can be bought either online or from your local garden store

once you have the seeds you want, you’ll need to germinate them from seed to sprout.

How to germinate lettuce seeds to grow hydroponically:

There are two ways this can be done, first you can just drop a couple of seeds into the growing medium. The growing medium needs to be soaked in water so the seed can get started, make sure these are in a warm area like a hot water cupboard or kitchen countertop as seeds need warmth to get started

Starting Lettuce Seeds: Snap-loc bag method

Alternatively, you can use the plastic bag method, my favorite. For this you just need a zip-lock bag and a paper towel. Then follow these steps:

1. Put the paper towel on a plate and add some water so the entire towel is wet (but not soaking)
2. Sprinkle some seeds around one quarter of the towel, then fold twice so the seeds are covered and the towel is 1/4 of the size.
3. Insert the paper towel inside a sandwich size snap-loc bag and sit on the window-sill to keep warm.
4. Once the seeds have opened up and grown 2 leaves, you can transfer into the growing medium to take hold (be careful not to damage the leaves)

Growing Lettuce Hydroponically: From Seedling

At this point, you have all of your equipment setup and have either bought some seedlings from the nursery / garden store, or you have germinated your own seeds. Congratulations, it’s time to get growing. In 30 days you could have a beautiful lush bunch of lettuce ready to be cut and eaten for dinner or on that Turkey sandwich.

To recap, you should have:

1. Growing tray
2. Water reservoir
3. Net cups
4. Growing medium
5. Nutrients
6. Seedlings
7. Lights (Optional)

There are only a few things you need to do now:

Fill up the reservoir

Place the growing tray on top of your reservoir and drop a net cup in one of the holes. you’ll want to fill up with your water-nutrient solution all the way until water touches the bottom of the net cup support. This will allow the roots to soak and drink the water, nutrients and oxygen from the solution that flows through.

Ensure the seedlings are sitting in the medium correctly

Place a seedling inside your growing medium and sit into the net cup. Make sure if there are any small roots, that they are free to grow downwards into the water

Turn on the lights (with timer)

Make sure your lights are turned on with a timer to run for 16 hours each day. This will allow the plants to absorb energy from the lights so they can transport sugars and water throughout the plant.

You’re Growing Lettuce Indoors!

After two weeks, you should be seeing small leaves growing on top of your lettuce seedlings, if not it means that your lights are not strong enough for the area covered (or if you’re not using one at all)

Sit back and enjoy the process!

It’s now time to let the plant do its thing. Keep an eye on the water level, if this drops more than half an inch, add more water/nutrient solution through the top with your watering can.

Once the plant has matured you can start trimming off the outside leaves and eating them, they will keep growing even after harvesting!

Let us know in the comments below if this was help