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How to sow and grow cos lettuce

Our cos lettuce - or Romaine lettuce - is a tasty, crisp type of lettuce. It can handle warm weather pretty well, better than ordinary lettuce. And, it's even healthier too.
Bindsla in de Makkelijke Moestuin
Cos lettuce

What is cos lettuce?

Cos lettuce has firmer leaves than head lettuce, so it's nice and crispy. This lettuce is very popular in the summer in Southern Europe. It keeps for a long time after harvesting.

Our cos lettuce is super compact, so you can fit 4 heads in 1 square patch of 30x30 cm.

How good for you is cos lettuce?

Cos lettuce contains about 5x as many vitamins and minerals as head lettuce. 

It's rich in vitamins A, B11, C, and K (folic acid), and also contains B1, B2, and B6. Plus the minerals manganese, iron, magnesium, calcium, phosphorus and copper and the amino acid tryptophan. And guess how many calories? None 🙂

So, cos lettuce is super healthy. 
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More about our cos lettuce

This cos lettuce is a cross between Romaine and your usual head lettuce in terms of flavor. It's delicously crunchy and can handle warmer weather. The mini heads grow compactly so they fit nicely in 1 square patch. 

  • Species name: Little Gem - Sucrine
  • Family: leaf
  • Plants per square patch: 4
  • Height: 15 to 25 cm
  • Sowing time: March - September
  • Sowing depth: 0.5 to 1 cm
  • Germination time: 5 to 18°C in 2 to 14 days
  • Time to harvest: after 6-8 weeks
  • Sunlight: can grow in sun or shade

We sell cos lettuce seeds separately, or as part of our seasonal seed pack: 

What do you need to grow your own cos lettuce?

You only need a few things to grow cos lettuce:
  • a 30x30 cm square patch with an airy, nutrient-rich soil mix
  • cos lettuce seeds
  • an area with at least 4 hours of sunlight a day
In other words: an MM-Mini, or a square patch in one of our garden boxes, filled with MM-Mix.

Growing your own cos lettuce is super easy with the MM-Mix. If you grow in low-quality (potting) soil, disappointment is pretty much guaranteed. So don't skimp on soil mix: go for the best.
Opgroeiende bindsla in een Makkelijke Moestuinbak
Medium-sized cos lettuce in a Planty Garden

How do you sow and grow cos lettuce?

Cos lettuce is included in the free Planty Gardening app. Use it, and you'll get step-by-step guidance from seed to harvest.

Each vegetable goes through a number of stages - we call them levels. The app tells you exactly what to do at each level and checks in when your plants are ready for the next.

So, you don't need to know how to grow cos lettuce before you start: the app takes you through every step.

But if you'd like to read more about those steps, here's what the process looks like:
Er passen 4 bindslaplantjes in een Makkelijke Moestuin vak

Level 1: Sowing cos lettuce

Choose a patch in the front 2 rows of your garden box. Make the soil mix loose and moist. Then sow the seeds like this:

  • poke 4 holes in the patch (no deeper than 1 cm)
  • put 2 to 3 seeds in each hole
  • carefully cover up the holes with soil mix

Depending on the weather and the time of year, you'll start to see something come up after about a week.
Zaailingen van bindsla in de Makkelijke Moestuin
Cos lettuce seedlings

Level 2: Cos lettuce seedlings

If you see the first seedlings, you know you're on track.

They probably won't all come up at once, but after another week, you should see most of them.

Then it's time for the next level. 

Level 3: Thinning cos lettuce seedlings

More than one seedling may come up in the spots you sowed. Choose the best seedlings and remove the rest: that's called thinning out. It might sound harsh, but it's necessary. The remaining plants will have the room they need to grow. 

So, you'll end up with 4 healthy cos lettuce plants.

If you see places where nothing came up, sow a few more seeds. 

And keep an eye out for snails: they love tender seedlings.
Klein bindsla-plantje, ongeveer 2-3 weken oud
Small cos lettuce plant, about 2-3 weeks old

Level 4: Caring for your cos lettuce plants

After a week or 2, your seedlings will become small plants.

You don't need to do much for the next few weeks: water the base of the plants if the weather is dry and remove dead or yellow leaves once in a while. Easy 🙂
Opgroeiende bindsla plantjes in de Makkelijke Moestuin
Caring for cos lettuce is easy

Level 5: Harvesting cos lettuce

At this stage, it's about 7 to 8 weeks after sowing and the plants are ready for the first harvest.

There are 2 ways to harvest:

Option 1:

Cut or pick the individual leaves. As long as you leave the center, new leaves will continue to grow.

Then you can keep harvesting for a few weeks.

Option 2:


Harvest the whole heads. Cut off 1 or 2 of the heads just above the soil mix. They'll probably be a bit small at first but really tasty. 

Let the remaining heads keep growing. You'll harvest them in the coming weeks.
Pluk wat blad van de bindsla af en laat de rest van de krop staan.
Cos lettuce plants with the outer leaves harvested

How do you use cos lettuce?

The crisp lettuce is a great for green salads. It goes well with all kinds of other lettuce. You can add fruit like apples or pears. Or use it to make a tasty lentil, pea, or bean salad.

You can also stew the leaves (briefly), or stir fry them. This is a great option when the plants are already flowering.
Oogstbare bindsla in de Makkelijke Moestuin
Cos lettuce: ready to harvest

The last levels

Keep harvesting the cos lettuce until the plants shoot up from the middle. This means that they'll start to flower soon.

That upward growth means it's time to harvest right away. The leaves won't be as tasty raw but are still good with mashed potatoes or in a stir fry.

The last level: empty your cos lettuce patch or your MM-Mini and prepare it for the next round of sowing.
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So: ready to grow your own cos lettuce?

It's an easy vegetable to grow, super healthy, and delicious. Great for summer salads. You'll rarely find this lettuce in the supermarket.

Plus: our materials and app make it practically impossible to fail 🙂

Get your cos lettuce seeds here or get started with a complete starter kit:
Enjoy!
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