Pre-sowing with vermiculite: how do you do that?

Want to grow your own summer vegetables? Then pre-sowing is the way to go. That means germinating the seeds indoors and transplanting them outside when they're strong enough.

You'll need some special pots, vermiculite, and MM-Mix. Your plants will grow much faster and stronger than with the usual pots and potting soil.
Pre-sowing my bush tomatoes with vermiculite
Pre-sowing my cherry tomatoes

What is pre-sowing you ask?

Most seeds can be sown straight into your garden box. They germinate, seedlings come up, and your plants grow big and strong.

When you pre-sow, you sow indoors.

Your seedlings grow in a greenhouse or on the windowsill. You give them just the right amount of light, nutrients, and warmth. When they're ready, you'll transfer them to your garden.

This page takes you through pre-sowing using MM-Airpots and a mixture of fine vermiculite and MM-Mix.

This works way better than just using soil or vermiculite in an ordinary pot. Also, it’s fast and easy to do.

What do you need to pre-sow?

You only need a few things:
The materials you need for pre-sowing: soil mix, vermiculite, seeds and a mixing bowl
Materials for pre-sowing at the ready

Here's how you do it:

Step 1: In the mixing bowl, combine 1 part MM-Vermiculite and 1 part MM-Mix.
Combine equal parts MM-Mix and vermiculite for indoor germination
Equal parts MM-Mix and MM-Vermiculite
Step 2: Pour in just as enough water so the mixture sticks together.
Adding water to the vermiculite and soil mix so it sticks together
Add some water
Step 3: Fill the MM-Airpots with your new mixture. Press it down gently with the rounded side of a spoon.
Fill the net pots with the mix of vermiculite and MM-Mix and press down gently
Fill up the pots and press it down gently
Step 4: Poke a hole in the middle of the air pot up to 1 cm deep.
Step 5: Cut open the seed bag and place 1 seed in the hole. Then gently cover it with some of the vermiculite-mixture.

(Our tomato seeds aren't cheap, so only sow 1 seed per pot. For other seeds, you can use 2 or 3).
To pre-sow our seeds, place one seed in each hole
Step 6: Put your MM-Airpot in a bowl or dish and leave it in a warm place.

If you're sowing different types of tomatoes, label them right away.
 
Put the air pots in a dish in the windowsill so they stay warm enough
Nice and cozy on the windowsill

So, what's next?

After about a week the first seedlings will emerge. It's automatic, they just show up one day. You don't have to do anything except check if the mixture is still moist. You should check regularly because seeds won't germinate without moisture.

As soon as you see seedlings coming up, put the air pots somewhere that gets the most light, but won't get too warm. 

Give the pots a quarter turn every day. This stops the seedlings from growing crooked. And again, keep the vermiculite mixture moist.
Tomato seedlings on the windowsill
Tomato seedlings on the windowsill

Windowsill care

Caring for your plants on the windowsill actually is kind of tricky. They want lots of light, but can't get too warm: that's important. So full sun, but not warmer than 20°C, preferably a little cooler. 

Keep giving them a quarter turn every day and keep the mixture moist. 
The yellow bush tomato -yellomato- growing up tall and strong on the windowsill
The baby yellomato. They grow up so fast.

Repotting, hardening off and moving out

At the end of April, transfer your plants to a larger pot full of MM-Mix. No vermiculite this time. A bigger pot gives your plant more room for its roots, so they'll continue to grow.

Once the end of May rolls around, let the plants get used to the outside. Start with an hour and then let them out a little longer every day. This is called hardening off.

After a few days, you'll move the most beautiful plant into its new home. 
Once a tomato plant has been hardened of, transplant it into the raised bed under a trellis
A young cherry tomato, freshly planted under the trellis

The app helps you step by step

Alright. So, that was a lot. But you don't have to remember it all.

Each step is written out and illustrated in the app. It also gives you the right instructions at the right time.
From starting your seeds to removing the plant at the end of the season. And everything in between. 

With the app, you pretty much can't go wrong. 

It's amazing, isn't it? You can grow so many tomatoes from just 1 tiny seed.
Pre-sown yellow bush tomatoes produce tons of cherry tomatoes
The yellomato in an MM-Mini

Ready to pre-sow?

The seeds, air pots, MM-Mix, and pre-sow vermiculite are in the shop. The rest you've already got 🙂
Have fun!

PS: Why do seedlings grow better in MM-Airpots than in regular pots?

Okay, so in regular pots, roots keep growing along the sides of the pot. They're so busy growing in endless circles, they don't absorb as many nutrients.

With the MM-Airpot it's different. These net pots have openings on the sides:
MM-Airpots are net pots with holes along the sides that give roots more oxygen
MM-Airpots
If a root comes too close to the side of an MM-Airpot, it stops growing. That's called air pruning.

Instead of the roots getting longer and growing in circles, the plant will then produce new roots over and over again. The result is a strong root system with lots of young and healthy roots that absorb air, nutrients, and moisture.
Air pruning at work: a regular pot produces long spiralling roots (left). A net pot creates compact, healthy root balls (right)
Left: A regular pot. Right: An MM-Airpot.
Your plants will grow faster and become stronger.

On top of that, you don't need to repot them as often. You'll also have less trouble transferring to your vegetable garden box or MM-Mini outside.
A net pot produces stronger seedlings: a tomato plant pre-sown in an MM-Airpot is much taller and has more leaves than one grown in a normal pot
What's the difference? Left: an MM-Airpot, right: a regular pot
We verkopen 2 maten potjes: de kleinere airpotjes voor de eerste tijd en de grotere airpotjes voor als je de tomaten overplant op alleen mix.

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