Growing Hydroponic Lettuce
They say the easiest things are the hardest.
And in the case of growing indoor lettuce.. I’d say that’s true!
I never really focused on growing my own lettuce until I got the Click & Grow smart gardens.
Mostly because I’m not a huge salad person and I always wanted to try growing more ‘difficult’ things. (Lettuce is supposed to be one of the easiest plants to grow hydroponically.)
So… I was surprised when I didn’t find it all that easy, ha.
Here’s everything I’ve learned from growing lettuce indoors – from harvesting, regrowing and storing.
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Click & Grow Salad Garden
Click & Grow’s smart garden 9 includes 3 green lettuce plant pods.
I also got their green salad kit, which came with romaine, sorrel and arugula.
Within the lettuce vegetable family, there are 5 main sub-categories of lettuce types:
- summer crisp
- butterhead
- iceberg
- oak leaf
- romaine
Even if you think you’re not a ‘salad’ person, you may actually like lettuce. You probably just haven’t found the right variety!
Although Click & Grow doesn’t really specify the exact names of the plants they offer, I believe their green lettuce is a summer crisp variety.
The romaine is, naturally, a romaine variety.
Technically sorrel and arugula are not part of the lettuce family, but are found in the greens section of the grocery store so we can consider them salad greens.
Arugula is one you’re probably already familiar with.
It looks like little oak leaves but has a strong peppery flavor and crunchy texture. I like sprinkling it on top of pepperoni pizza, fresh out of the oven.
It’s also a great textural addition to summer salads.
Sorrel you may be less familiar with (at least, I had never heard of it).
Read more: Click & Grow Review: Is the Smart Garden Really.. Smart?Sorrel is popular in Eastern European cuisine (think borscht) and is technically a member of the herb family.
The plant’s edible leaves are harvested for their sour, peppery flavor. I’d describe it as a stronger, more pungent version of arugula.
One of the things I like most about indoor gardening is discovering new vegetables and experimenting with ‘tastier’ varieties of vegetables I thought I didn’t like!
Read more: Everything You Need to Know About Indoor Gardening
my indoor salad garden progress, from seed to harvest!
Growing Lettuce Indoors
I believe it’s incredibly rewarding to grow your own lettuce.
Lettuce is one of the vegetables that’s frequently recalled from grocery stores for e.coli and various other bacterial diseases.
Growing your own is the safest way to ensure your produce is pesticide free and 100% clean.
And doing it hydroponically makes it easier!
Seed Starting
I popped in Click & Grow’s plant pods and started to see baby seedlings in just a couple days.
Lettuce germinates very quickly, in about 2-4 days.
They’re probably the fastest growing plant.
And even better, when you grow lettuce indoors hydroponically, it grows significantly faster than in a traditional outdoor soil garden.
lettuce progress in just 2 weeks
About a week in, I decided to thin out some of the extra seedlings.
Click & Grow also over-seeds its plant pods to ensure that you’ll have something that germinates.
It depends on the plant type, but I usually remove the extras and leave just 1 plant per pod, so that it has enough space to grow.
I have a tutorial on how to do this and save the extra seedlings in this post.
I hate waste and killing off perfectly healthy plants seems like such a waste!
it’s pretty easy to remove the extra seedlings and save them to plant separately!
Thinning
In hindsight, I would recommend thinning the green lettuce and romaine but not arugula and sorrel.
Green lettuce is a frilly summer crisp style of lettuce that starts off open, similar to a loose leaf, but then matures into more of a compact ‘head’ style lettuce.
Romaine forms a compact, rosette shaped head.
But arugula and sorrel grow to a taller, thinner style – similar to herbs.
They don’t require as much room. I think you could easily leave 4-5 seedlings per pod and not have crowding issues.
arugula and sorrel can be thickly seeded and be just fine, space wise!
Growth & Nutrition
The nice thing about Click & Grow’s gardens is once you ‘plant’ the pod… their smart gardens basically do all the work for you!
About 30 days in, the lettuce and salad greens were thriving.
one month in, the romaine and green leaf lettuces were ready to harvest
Each smart soil pod has nutrition beads, and lettuces are easy going plants that don’t require much in the way of nutrients.
So I just watched the plants grow all on their own, without really lifting a finger.
Occasionally I monitored the water float and topped up the tank with more water.
Note: I got a lot of questions on Tiktok about mold growing in the Click & Grow garden.
The key to preventing this is not to overwater. Err on the side of less water, rather than more.
And if you are seeing an excess of mold or algae, try to cover the surface of the smart soil pod.
The plastic covers do a great job at covering 85% of the plug, but you can stick a piece of aluminum foil underneath to block out light completely on the small exposed portion.
Harvesting
Lettuce is a fast growing plant.
Each variety is slightly different, but lettuce will mature anywhere from 28 to 60 days.
I find that loose leaf types mature the quickest.
Lettuces that form heads can take a little longer to form a large, compact head – about 30-40 days.
You want to harvest your lettuce at peak maturity, in order to eat not only the freshest tasting produce but also one with the most nutrients.
Click & Grow says its lettuce has double the level of antioxidants than bagged lettuce that you get from the supermarket.
That’s because grocery store lettuce is often picked in advance, and once cut, lettuce rapidly deteriorates.
How to Cut Lettuce from Click & Grow
You can either continually harvest lettuce as it grows or wait until the lettuce is full grown and harvest the entire thing.
The first method is called the ‘cut and come again’ method because you can make little snips and the lettuce will keep growing.
one month in, the romaine and green leaf lettuces were ready to harvest
For the ‘cut and come again’ method, you can either:
1. Cut the outer leaves
Lettuce grows from the center, outwards. So as long as you harvest the outer lying leaves, the plant will continue to produce.
2. Give the Plant a Haircut
Cut straight across the top of the lettuce, taking no more than 1/3 of the plant. As long as you ‘haircut’ the lettuce above the center growing tip, it will continue to produce.
There’s no right and wrong way to cut lettuce, it’s up to you!
I like to leave at least a couple plants alone to reach full size, so I can harvest the entire thing at once.
And I also like to cut the outer leaves from some plants because often, the plant will focus on growing and neglect some of the outer leaves.
You’ll notice the outer ring of the plant can yellow and die off.
Harvesting these often is a good way to eat the full amount of the plant without letting any of it waste.
Bitter Lettuce
There’s an art to harvesting lettuce.
Often, people will complain that their home grown hydroponic lettuce is tasteless or bitter.
Taste is heavily affected by the nutrients you’re feeding your plants.
Give too little, and your plants will taste bland and flavorless. Give too much, and they can taste bitter.
Because the Click & Grow pods have built-in nutrition beads within the smart soil pods, you don’t have to worry about over or underfeeding your lettuce.
So I think the company simplifies the most difficult part of the growing process!
sorrel gets more sour and pungent as it matures. harvest by week 6 for the best taste!
How the Click & Grow Salad Greens Tasted
I liked the taste of all the salad greens grown in the Click & Grow.
The green lettuce tasted just like the grocery store (light, crunchy without too much flavor) and the arugula and sorrel were much spicier.
The romaine was crunchy and crisp.
If you leave lettuce too long, you may find that it turns bitter.
So if you’re new to indoor gardening or growing lettuce, it’s best to harvest early frequently.
Bolting
As lettuce reaches the end of its lifespan, it will bolt.
You’ll notice it right away, because the lettuce will look different. The center shoots up, straight and tall like a stalk, instead of staying low and bushy.
Eventually, it will flower and go to seed, producing seeds for the next generation of lettuce.
Once lettuce has bolted, it tastes downright awful so you’ll want to harvest your lettuce before this happens.
The leaves will taste bitter and you’ll notice a milky sap from the cut leaves.
i would recommend this green lettuce if your house is on the colder side, as it bolts quite easily
Bolting can also happen on accident.
In the wild, lettuce is triggered to bolt by the temperature. Lettuce is a cool weather crop, meant to be grown strictly in the fall and winter.
Warm temperatures, or a sudden change in temperature from cold to warm, signals to the lettuce that the ‘seasons’ are changing and that it’s time for the lettuce to die off and produce seed.
So if you’re growing lettuce indoors, you’ll want to carefully monitor your home’s temperature.
the green lettuce was at the end of its lifespan while the chili pepper was in its middle life
You can grow lettuce all year round inside your home as long as you keep the temps on the cooler side (ideally 50-65 degrees).
Sometimes I add small ice cubes to the reservoir. This also helps crisp up the lettuce leaves!
Even just one hot day can cause a finicky lettuce to bolt and there’s no recovering the plant once it’s bolted!
That happened to one of my romaine lettuces.
dark-green romaine at its peak on the left and post-bolt, with yellowing leaves on the right
I held off on harvesting because I was waiting for the cos lettuce to get as large as possible.
The veggie is so pretty (it grows in a round rose like shape) that I wanted to time the harvest for its peak maturity.
Then we had one crazy warm day in NYC and the romaine bolted :(
So much for all the work in growing it!
If any of your lettuce do bolt, you can wait for the plant to go to flower and save the seeds. It’s a nice silver lining to having all your hard work blow up.
Storing Lettuce
Once you cut lettuce, it will rapidly wilt and start to deteriorate.
In fact, it happens so quickly (in ~30 minutes) that I wondered how grocery store lettuce stayed crisp for so long. That’s when I found out store bought lettuce has been sprayed with a preservative to maintain crispness.
Even the organic ones! Organic doesn’t mean no chemicals whatsoever, there’s just a list of approved chemicals.
When harvesting your own lettuce, try to cut it right before you want to eat it.
a reader recommended I use all the sorrel to make green borscht! so that’s what I did :)
To crisp it up, you’ll want to give it a cold soak.
Place the lettuce in a big bowl of cold water and leave it for 20-30 minutes. The cold water will re-hydrate the lettuce and crisp it up so it won’t get so soggy.
Then, you can either use it or store it for later.
If you want to keep it in the fridge, make sure to fully dry the soaked lettuce.
Use a salad spinner to get it completely dry.
Then place it in a plastic container with either a paper towel at the bottom or a kitchen towel wrapped around the lettuce.
You want a plastic container to minimize oxygen (which further deteriorates the lettuce) and a towel to absorb moisture from the lettuce and fridge condensation.
Place it in the crisper drawer of your fridge.
The bottom section of a refrigerator helps preserve freshness by operating on a higher humidity to trap air inside and encourage less water to evaporate from your lettuce.
I really like this container – it’s a storage container specifically designed for produce.
Inside there’s an elevated colander to lift the produce away from the outer rim of the container, which encourages airflow to prevent rotting.
And there’s also a carbon filter inside to trap ethylene gas which helps slow down the aging process.
And that’s my quick guide to growing lettuce indoors.
Let me know if you have a favorite lettuce variety or other helpful hydroponic lettuce tips!
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