How to… Easy Grow Lettuce
We’ve had great success growing lettuces and salad greens from seed with Hydrofeed Complete. Not only is this easy to set up, with minimal equipment, you get fast results compared to other plants (we’re looking at you strawberry chillis). You can grow your own salad fast and fresh, with no pests* munching through your salad. Keep reading and we’ll walk you through a simple set up to grow greens of your choice. Anyone of any age can get involved, but children should be supervised as chemicals and sharp objects are involved.
* We make no guarantees but growing indoors without soil greatly reduces the risk of bugs finding their way onto your plants.
Equipment needed:
Essentials:
1. Inner tub - A small basket or pot (we’ve set this up using a yoghurt pot and some hydroponic baskets) a basket would be better but give it a go with whatever you have to hand.
2. Outer tub - A tub larger than the inner tub used that the basket/tub will comfortably fit within, with some free space underneath to allow roots to grow out and give you some space for nutrients. The inner basket or tub will need to sit on the top of the outer pot. You can do this by cutting a hole out of the lid, like in the picture below, large enough that the basket or tub can fit in but small enough that it won’t fall through. If you’re using a light or clear tub for your outer tub, we recommend dark paper or plastic to cover the exterior of the tub, this reduces the risk of growing additional greenery in the water (algae).
3. A “growing medium” – this is the structure the plant’s roots will grow into. You can use perlite, which is available from garden centres, or vermiculite. We’ve used spare rockwool in the past when experimenting with new plants, this is a type of insulation.
4. Seeds (your choice of lettuce or salad leaves).
5. Hydroponic nutrients – you can get hydrofeed part A and B from our shop, or any equivalent hydroponics nutrient will do the job. This is what feeds the plants and helps them grow, like the vitamins and minerals in our diets.
6. Lighting - any light will do, but you can speed things up by buying a specially designed light fitting or bulb that uses the right kind of light for growing plants indoors. Windows often have coatings that block certain types of light, so your plants may not grow well on a windowsill without a little help. Plants use light to make sugar (glucose), which gives them energy to live and grow. Alternatively you can put your lettuce outside and grow under a plastic cover to keep the rain (will dilute your nutrients) and bugs off.
Optional:
1. Reflectors to focus the light from your chosen light source onto the plant(s). You can use kitchen foil wrapped around pieces of cardboard for this, this works quite well.
2. pH meter (see glossary at the end of this page) – lettuce grows best at a pH of about 6. You can get a cheap pH meter for about £10 , or use pH strips. You can also try a red cabbage pH experiment!
3. pH up or down – we stock a safer alternative to the typical pH adjusters, but other options are available. Tap water is often neutral or slightly alkaline however plants generally prefer a slightly acidic nutrient solution, typically pH 5.8 to 6.2. A bit of pH down can sort this straight away!
Method:
1. If using a pot for the inner part of your set-up, poke some holes with a pen, scissors or other sharp object. This lets the nutrients get to the new roots and allows the root to grow out as the plant grows. If you’re doing this with young children or are particularly accident prone, we suggest a responsible adult does this bit.
2. Fill the inner tub/basket with your chosen medium. We’ve used perlite.
3. Put the seed(s) you’re planning to use in the medium. You can put a few seeds in, and thin these out if multiple seeds germinate. You can see a salad leaves seed in the middle of the perlite medium.
4. If you have a pH meter, we recommend adding pH up or down to the water you’re planning to use to reach the best pH for your plants (around 6 for lettuce).
5. Fill your outer tub with water so that the medium is partially submerged but not fully (the seed(s) should be above the water level).
Now you’re ready to put your inner pot in your outer pot. This is our final set-up.
On the left we’ve used baskets in an empty spread tub, on the right we have the yoghurt pot in a can.
Have a look at our blog to see how quickly our winter lettuce grew.
6. If you’re using perlite, the water won’t be drawn up to the seed, so use a small amount of water/ nutrient solution to wet the seed every day or so to keep it moist. We use a pipette for this.
7. When the seeds have germinated (start growing), swap the water for a mixture of water and nutrients. We use 5ml of each nutrient for 1 litre of water, but check the instructions of whichever nutrient you choose.
8. You’ll need to change the water regularly to maintain the nutrient levels and keep your plant(s) thriving. We recommend once a week, using the same nutrient/ water solution. Why not experiment with this and change the water at different times for different plants to see if more frequent changes make plants grow faster?
Stay tuned for experiments you can try as your plants grow!
Glossary:
pH – this is a measurement of how acidic a solution is. A low pH (<6) is acidic (like vinegar), a high pH (>8) is alkaline, like baking soda. Pure water has a neutral pH, around 7. To increase pH, or make a solution more alkaline, use pH up. To lower the pH, or make a solution more acidic, use pH down.
Growing medium – the material you’re growing the plant(s) in, you can use perlite, vermiculite, or a mix of the two. Vermiculite will soak up water like a sponge, whereas perlite acts more like pebbles and just provides a structure for the roots to grow. You can experiment with different growing mediums to see how they affect the growth of your lettuce.