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How to grow microgreens at home
(it's easier than you think)

So, what are microgreens and why should you consider growing them at home?

Microgreens are simply young vegetable greens, harvested about 7-10 days after planting. As a result of being harvest so early, they have incredibly high nutrient levels (up to 40x higher than mature veg). They also normally have more intense tastes and delicate textures than mature veg.

Some of the most popular varieties of microgreens are radish, broccoli, kale, sunflower and pea. They can be grown from the same seeds as mature veg. 

So for example, the same broccoli seeds can be used to grow broccoli microgreens as are used to grow full heads of broccoli. The big difference is that a full head of broccoli takes about 120 days to grow whereas broccoli microgreens only take 10 days from seed to table! 

The really exciting thing about microgreens is that they are incredibly easy to grow. In fact, you can grow them indoors at home without any fancy equipment or gardening know-how. Growing at home means that you and your family can have nutrient-packed, tasty greens which are harvested only seconds before eating them. You can’t get fresher than that!

Now lets to dive into how you can easily grow microgreens at home.

Broccoli microgreens would require 158–236 times less water than it does to grow a nutritionally equivalent amount of mature vegetable in the fields of California’s Central Valley in 93–95% less time and without the need for fertilizer, pesticides, or energy-demanding transport from farm to table.

Carolyn F. Weber, Idaho State University

What you'll need to get growing:

It doesn’t take much fancy equipment to grow microgreens but it is important to get it right so that the rest of your growing process is straight-forward and successful.

Something for them to grow in

The best (and easiest): A microgreens grow tray. This is basically a plastic tray with water sitting in the base and another mesh tray sitting just on top of the water. The microgreens can grow on a paper-like growing sheet or soil, placed on the mesh tray. As they grow their roots dangle down into the water below and soak up exactly the amount they need, there’s no chance of under or over-watering).

If you don’t have easy access to potting soil or live in an apartment then using a growing sheet can be really handy. It means that there’s no lugging soil around and no mess in the house.

If you do have access to potting soil or coco coir then it’s nice to use it as the microgreens like having some soil to dig their roots into and support them. (They’ll typically grow 10-20% faster and bigger in soil than in growing paper). You can get these trays here.

The garden centre option: The next option is to use a plastic tray (with holes in the bottom) and a watering tray (without holes in the bottom). You can normally pick these up in garden centres. The tray gets filled with soil and the microgreens are planted on top of the soil. Then the growing tray sits on a tray (without holes) that has water in it. So the microgreens suck up the water they need from the bottom.

The drawback here is just that you always need to use soil, growing paper is a no-go on these trays. Also, the trays typically only have a scattering of holes across the base of the tray so they don’t allow the micros to soak up water as effectively as the mesh tray in a microgreens grow tray.

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The DIY/give-it-a-go option: Take a tupperware or other suitable container from your kitchen, fill it with soil and plant microgreens on the top. In this case you’ll have to water from the top each day which isn’t as good for the plants as watering from the bottom but it should work for you to get started growing.

Micro Broccoli in the grower's hand.
a bunch of broccoli microgreens
Broccoli Microgreens
Red Aztec Amaranth Microgreens
Sangria Radish Microgreens

Seeds

Microgreens grow from the same seeds as regular plants. So if you want to grow sunflower shoots, you can grow them from standard sunflower seeds. Seed producers also breed seeds specifically for growing microgreens which are bred so that the seed is perfectly suited for microgreens. But you can start out with normal seeds, no problem.

The thing to consider here is seed density. If you take a pack of seeds from the garden centre, the packet is usually tiny (often 3-4 grams). When you grow microgreens you spread seeds really densely across the soil, since each seed is only going to grow one individual shoot.

Typically for a small tray used to grow at home, it will take 5-7 grams of seed, up to 9-11 grams for a larger tray. So the issue with garden centre seed packs is that it will take a whole packet (or more) just to fill one tray. Also, these garden centre seed packets usually cost 3-4 euros. This price is fine if you’re using them for home gardening where you only need a small quantity of seeds to grow mature plants. However, for microgreens, spending 3-4 euro to seed a single tray isn’t the most economical option.

That’s why we offer a monthly Grow at Home subscription. Get 4 tasty microgreen seed varieties delivered to your door in the exact quantities needed to seed a tray (plus all the equipment you need). You can check it out here

Top tip: You can grow pea shoots using dried marrowfat peas from the supermarket! Just take the dried peas, soak them for a day in a tub/bowl of water and then plant them in your tray.

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Growing Medium

Ok, so ‘medium’ is a bit of a fancy word, all it means is the material that the seeds are growing in.

If you’re using a microgreens grow tray: You can choose to use either a layer of soil (basic potting soil or coco coir) or a sheet of growing paper (similar to kitchen roll but specifically designed for growing microgreens). They grow a little bit faster/bigger in soil but you can save on mess/cleanup/expense by using growing paper, so it’s up to you!

With the growing paper, the seeds sit on top of it and it supports the seeds while holding just enough water for them without letting them get waterlogged.

As the microgreens grow, their roots push down through the paper/soil and into the water tray below. The big benefit here is that the plants stay dry and well supported while just their roots make contact with water. This helps to prevent waterlogging and mould issues which can occur if the plant itself gets wet.

If you’re using a plastic tray or tupperware: The medium will be basic potting soil or coco coir. Potting soil from the garden centre works just fine for microgreens (just make sure it’s clean and isn’t manure-based).

If you want to get serious about growing, you could look at getting coco coir, which is a soil made from ground-up coconut husks. It’s been shown to be even better for growing micros than regular soil. The only downside is it’s not available at most garden centres and needs to be ordered from a speciality growing store. (It is quite reasonable, however, at about €13 for a 50L bag)

microgreens growing under led lights
Sunflower Shoots happily growing at our vertical farm in Malahide.

Some nice to haves

A simple spray bottle: This can be an old empty spray container from the kitchen (cleaned out really well) or you can pick up spray bottles at the garden centre also. This is used for spraying the seeds to keep them moist during germination.

Vinegar: Some microgreens (sunflower, pea and wheatgrass) are prone to mould. Soaking the seeds in a mix of water and vinegar for an hour or two really helps to prevent this.

Ok, now we’ve got all the equipment together and we’re ready to grow! Let’s dive into the growing process (it’s not that hard at all):

Germination (fancy word but it just means getting the seeds to start growing)

Germination is just the name for the seeds ‘realising’ it’s time to grow and starting to put roots downwards and shoots upwards. So, how do you let the seeds know it’s time to grow?

There’s two key ingredients; moisture and warmth. The seeds need to be kept moist (but not too wet) so that they can soak up water, expand and kickstart their growing process. It also helps a lot if they’re nice and warm (about 20-24° celsius is perfect). Don’t worry if your house/apartment is slightly cooler, they’ll still germinate it’s just a bit faster if they’re warmer. Having said that, they really shouldn’t be below 15° C or things will go really slow, so make sure they’re indoors in a nice warm spot!

 

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A variety of microgreens growing in trays of coco coir under LED lights at our farm.

The step-by-step germination process

1. Place your growing medium (soil or growing paper) onto your tray. If using soil, remove any clumps, spread it evenly and press it down a bit with your hand or a flat surface.

2. Give the growing medium some water. For growing paper, use a spray bottle to soak it (enough so that it changes colour and sticks to the tray, but not absolutely saturated). For soil, use either a spray bottle or a watering can to give it a good soak. The soil should be damp throughout but not saturated/waterlogged.

3. Spread your seeds over the top of the growing medium. You want them to be pretty densely spread (try to imagine each seed being just one shoot and it will give you an idea) but not touching/overlapping. You can shake them from the packet, sprinkle from your hand or (our personal favourite) use a takeaway coffee cup with the lid on, so the seeds gently shake through the sipping hole in the lid.

Side note: If you’re growing pea shoots, sunflower shoots or wheatgrass then it helps to soak the seed in water overnight before planting them. Just stick them in a bowl or container of water and let them sit for 10-24 hours. They’ll soak up water and germinate better. If you have vinegar handy and want to reduce the chance of mould for these plants, mix about 30ml of vinegar with 300ml of water and soak them in this for 1-2 hours. Then rinse them and soak them for 10-24 hours in tap water.

4. Now, give the seeds another little spray, just to get some moisture in direct contact with them.

5. Cover them up. For the microgreens grow trays, you’ll just take the base tray and place it sitting on top of the seeds. With garden centre trays, you can use the solid watering tray or any hard surface (maybe a tupperware or placemat) and put it on top of the seeds.

6. Put some weight on top. Four cans of beans is a nice handy weight for this but you can use anything you have handy that weighs about 1 – 1.5kg. Just place it on the tray or surface you have covering the seeds.

The covering tray is going to keep the seeds dark (so they think they’re under the soil and need to grow up fast to reach the sun) and the weight will force them to build nice strong roots and push up hard against the weight (they’re stronger than you think).

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So what now? Just leave them like this for 3-4 days. Each day you should check on them and if the soil/paper looks dry, give them a little spray of water to keep them moist and then re-cover them.

After 3-4 days, they should be pushing up against the covering tray and have good strong roots. It’s time for blackout!

Microgreens actually grow faster in the dark for the first couple of days. It’s like they’re racing up trying to find the sun as quickly as they can.

So at this point just take the tray that was covering them with the weight in it and turn it upside down (so it looks like a dome). Then place it on top of the growing microgreens so that they’re in the dark but free to grow upwards.

If you don’t have a tray which works as a blackout dome like this or there isn’t enough space under the upturned tray for the microgreens then you can skip this. They’ll still grow just fine, this just speeds things up a bit.

Just leave them under the upturned tray in darkness for a day or two and they should be shooting up tall and straight. Now, onto the growing phase!

micro kale
Micro Kale looking good!

The Growing Phase

Once, the microgreens are shooting up and have nice strong roots, they’re ready to go into the light. What light can you use? A windowsill or sunny area in your house that gets a nice amount of natural light is perfect.

They’ll also grow well under artificial light, so you can try putting them directly under some lights in your house that are on all day. They grow best with at least 12 hours of light a day.

Now, all you have to do is keep an eye on the microgreens and water them each day. By far the best way to do this is bottom watering. This just means the micros are sucking up water from below with their roots. Using a microgreens grow tray is perfect here, you just add water to the base tray each day and the micros suck it up as they need it.

If you can’t water from the bottom because of the tray/container you’re using, then you can just water carefully from the top using a spray bottle. Try to get as little water on the plants themselves as possible here. The issue with watering from the top is that if the plants get too wet they can get mouldy/diseased. However, it can do the job for you to get started once you water carefully.

How much water and how often?

Start off with about 100ml of water for a small tray, just add it to the base water tray and let the plants soak it up. Come back after about 10-20 minutes and if it’s all soaked up, add a little bit more.

Then, each day check the base water tray and if it’s empty just top it up with a little water.

All that’s left to do is watch how quickly they grow and admire your work!

Pea shoots on a risotto dish
Radish microgreens complimenting a risotto dish

Harvesting & Storing your tasty microgreens

Once the plants are about 7-10cm tall then it’s time to harvest. How long will they take to reach this size? Here’s a quick guide for a few popular varieties:

Pea Shoots: Germination time = 3-4 days, Grow time = 7-9 days
Radish Microgreens: Germination time = 3 days, Grow time = 5-6 days
Sunflower Shoots: Germination time = 3-4 days, Grow time = 6-7 days
Broccoli Microgreens: Germination time = 4 days, Grow time = 7-8 days

So, in total you’re looking at about 8-12 days to go from seed to tasty microgreens on your plate, pretty speedy!

So how do you harvest? We recommend using a pair of scissors for greatest ease (a knife will also do). Best practice for harvesting is cutting the microgreens at their base about a centimetre above the soil/growing paper. Feel free to harvest bunches together at a time, but be gentle as to not tear them.

After harvest, it is best to keep them between damp paper towels, and make sure they are cold and covered in a resealable bag or container. Wrapped this way, they’ll last in the fridge for about a week.

Or, you can harvest the micros as you need them, so if you fancy some for dinner just cut a handful and enjoy! Don’t let them grow for too long though or they’ll lose the tender texture and taste which microgreens are known for.

It’s up to you whether to rinse them or not. You definitely want to make sure there’s no soil on the greens so if you use soil, giving them a quick rinse is a good idea. Also, make sure to only rinse them right before use, otherwise, they can get soggy if left wet.

baked brie with sunflower shoots
Radish microgreens accompanying a baked brie dish.

Eating your microgreens (the best bit!)

Now it’s time to get creative. Microgreens are full of colour and full of taste, so they are a beautiful garnish for all kinds of meals. 🌱

The simplest way to use them is just to sprinkle a handful on top of your meal, added flavour and wow-factor in an instant!

They’re also great in sandwiches/burgers to replace lettuce and can even be blended into smoothies/juices for a nutrient boost.

What are some of our favourites? Here’s a few:

  • Omelettes/Eggs (of any type)
  • Ramen
  • Curries
  • Salads (Adds a serious kick of flavour and colour)
  • Stir-fries
  • Wraps and sandwiches
  • Pizza (Just sprinkle on top)
  • Fajitas
  • Pasta dishes
  • Smoothies
  • Avocado Toast
  • Soup

They don’t need any cooking, so most people add them to dishes just before serving. The bonus here is that they don’t lose any nutrients during cooking as mature veg does.

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Conclusion

Hopefully, you’re excited to start growing your own microgreens at home now! They really are easy to grow and have incredible flavour and nutrients for such a fast-growing, low maintenance plant.

If you need any help choosing/finding equipment or are having any troubles with your home growing, reach out to us and let us know. We’ll always do our best to help you. You can email us at hi@upfarm.ie

Thanks for reading this far and happy growing!

PS: If hunting down all the equipment and seeds sounds like a hassle, consider checking out our Grow at Home subscription: everything you need to grow, delivered to your door monthly.