Professional microgreens on your window sill - and why you should use a 3D printer for it
Microgreens are awesome. With just a little dash of those tasty leaves you will make every dish look like it's chef made. For best taste freshly harvested microgreens are essential. That eventually translates to: Grow them at home, it is worth it!
How to grow them?
Glad you ask! It is as easy as it can get. There are two major techniques to grow microgreens. And do not worry, we will get to the 3D printing part in a second.
The easiest is a sprouting jar. That means, you take a jar, add the microgreen seeds and close it with a mesh. Then you just rinse it with water every day, until the seeds start to sprout and grow. When you place the jar upside down the mesh helps the water to escape, so the seeds will not rot. Plants have enough energy in their seeds to sprout and grow until the first pair of leaves, which is when you want to eat the microgreens. And that is really it. No further magic, nothing more needed: A jar, a mesh, seeds and water. I recommend a look into this blog article just about that technique.
If you feel even more fantastic you can grow microgreens in a substrate. That is the slightly more advanced method for microgreens. Though you will have a bit more work it will give your microgreens an even better taste, because you will be able to add nutrients if you feel like it.
A little bit less ultra easy
For that we will need a tray for the substrate and the seeds, among some other things that will help us. Unfortunately it is not as easy as "throw-your-seeds-in-the-soil-and-harvest-when-ready". I looked up what professional microgreen growers do on a large scale and sized it down to a 3D printable window sill version. Hence you will be able to grow professional quality in personal home sizes. If you want to look up how the kit has been designed, improved and printed (and also how you can print it at home) check this video.
And now let us continue here step-by-step:
We need a tray for the substrate. As the roots need space for development and we want to allow the water to drain it should have holes.
I assume you do not want to wipe away the water that comes out of the holes of the upper tray, hence a bottom tray that collects the water is necessary.
So far, so good. Let us continue with the soil, seeds and water.
Now we can add the soil (or any other growing medium you prefer) and the seeds. For easier sowing I designed a mesh with a funnel, that fits the tray.
When the seeds are on the growing medium you will want to water them. For this a spray bottle is the perfect tool, as it evenly distributes the water on the seeds and it is easier to find the right amount of water.
When using soil you do not have to add any nutrients, as the soil contains them most likely already. If you use different growing media, like rockwool, coco or perlite I recommend to add some liquid nutrients to the water. To find the perfect fit just search for your microgreen type and the recommended nutrients online.
While this is all pretty straightforward and nothing all too special for microgreens, now is the time where the magic starts. And believe me, I tried to grow microgreens without this technique and frankly speaking it was a mess. Yet the solution is rather simple, but genius, you need a pressure plate. That is it. A plate, that pushes the seeds down. This helps the seeds to root better into the soil and will eventually cause them to grow straight up. Otherwise the microgreens will fall over and make it almost impossible to harvest them. That being said:
Place the pressure plate on top of your seeds. Make sure, that it firmly clips into the holes on the sides.
Now we start the water and wait cycle. Microgreens like water twice a day. I admit, they will probably also survive if you only water them once per day, though twice will keep them happier. Watering is quite easy, you just need to know how to do it right.
Remove the pressure plate
Spray them from the top with water (or water + nutrients solution) until they are moist
As soon as the roots grow out on the bottom, also spray them from the bottom to keep the roots wet
Put the pressure plate back on
And that is it. You know officially know how to water microgreens. There will be a morning where you wake up, go to your microgreens and see, that the pressure plate has been popped off by your seeds. This is how you know, that you no longer need it. And more great news: There is only two steps left before harvesting. And the next one is the last trick you need to know to make your microgreens look like they come from a pro grower. We want our microgreens tall. For two reasons:
They are easier to harvest and you have more microgreen
They look (and probably also taste) better
Achieving this is again fairly easy. You just need to make the plant think it is still underground. And that is simply done by a cover box, that keeps it dark. So we continue like this:
Use the cover box like the pressure plate for another two to three days (or until the microgreens grow up to the ceiling of the box)
Remove the box and place the microgreens at the window sill or under a bright light (like really bright) to let them gain all their taste and color
The time for maturing will depend on your specific microgreen, which is about 6-8 days for red radish or up to 14 days for e.g. sunflower
And this leads us to our final step: Harvesting. Which is probably also the easiest of all the steps in this tutorial. Take a pair of scissors and cut the microgreens as close to the substrate as possible, but far enough to not harvest soil as well. As a rule of thumb I usually go with about 0.5cm above the substrate. Now enjoy your home grown microgreens.