Hydroponic Microgreens – A Complete Guide

It’s hard not to see why 21^st century gardeners are a little obsessed with hydroponic gardening. Taken as we are with science fiction fantasies of shiny, futuristic roof-top farms on skyscrapers — the reality of hydroponics is thankfully far simpler.  Put plainly, hydroponics is gardening sans the soil, with the seeds sprinkled on a contained bed. If you get everything right and optimize your growing conditions, you can grow way more food in less space with less water and less time.  Here’s how to enjoy a whole lot of microgreens without so much as getting your hands dirty. Read on to learn how to start your own hydroponic microgreens garden.

Why Use Hydroponics for Microgreens? 

Get sprouting. 

Plants do not need soil to grow, or even really to flourish — that’s what makes hydroponics so successful. Doing away with soil means you can grow in clear tubing or vases or even bowls without the use of media of any growing media. That’s way less dirt and mess right there, not to mention that you also needn’t worry about over- or under-watering. 

Almost any plant can be grown this way; however, there are candidates that are particularly suited to the technique – and none quite as ideal as microgreens! These are essentially the baby-seedlings of any plant with edible leaves, and they’re immensely rewarding to grow. Nifty, quick harvesting and packed chock full of nutrients, microgreens are a straight-forward, cost-effective addition to every pantry. 

And delicious to boot. 

What Microgreens Should You Grow? 

Bountiful and hardy, these mini vegetables offer a wide range of spectacular flavors. 

Plenty of popular vegetables make great micro leaves, packing a headier flavor than the mature plant! 

Try sunflowers, snow peas, fennel, coriander, chervil, broccoli and rocket. Some are perfect for adding a little extra oomph to a salad, with bright stems and bold leaves – try purple radish and the Swiss chard ‘Bright Lights’, which has red, yellow, orange and purple stems.

The Four Categories of Microgreens: 

• Shoots and tendrils like peas, sunflower and corn 
• Spicy greens like arugula, radish, cress and mustard
• Micro herbs like parsley, fennel and chrysanthemum 
• Tender greens like red cabbage, broccoli and spinach 

Steps to Growing Microgreens Hydroponically 

A good hydroponics setup requires a few basic elements. 

1. Growing Trays 

Most microgreen gardeners opt for a standard 10” x 20” plastic tray setup. Be sure to buy some with holes or poke them yourself. 

2. Microgreen seeds

Buy organic seeds intended specifically for growing microgreens. Avoid seeds treated with fungicides. 

3. Lights

Let those lights shine! Growing lights provide the same range of light as the sun and you’ll see much faster growth. 

4. Growing medium

Since you’re not using soil, you’ll need a medium to help secure the plant’s roots in place. Many mediums also help keep roots moist between waterings. Popular choices include coconut coir and hemp. 

5. pH test kit or strips

You’ll need these to keep tabs on the pH of your water to ensure it remains at the optimal level needed to ensure your microgreens thrive.

6. A spray bottle

This one is pretty self-explanatory! 

7. Nutrient solution

You’ll need a nutrient solution made up of all the macronutrients (think nitrogen and phosphorus) and micronutrients (like iron and calcium) that your microgreens need. 

It’s All About Maintaining Balance

You’ll have yourself a bountiful harvest of microgreens in no time at all if you follow our step-by-step checklist! 

1. Balance the pH of your water: 

You can’t forego this first, most important step — microgreens seeds are incredibly sensitive to the pH of water and you’ll want to aim for anywhere between a pH of 5.5 to 6.5. 

2.  Prepare your trays: 

Pour 2 cups of pH balanced water into the bottom of your tray, following which you’ll want to start laying your growing pads down. Ensure your pad is saturated, and then mist about 10 times. 

3. Distribute your seeds evenly: 

Spread dry seeds directly onto your soaked growing pad. Ensure you’re sprinkling evenly: for smaller seeds, you’ll want to use about 2 whole tablespoons, whilst larger seeds like radish can even be distributed in quarter cup measurements. 

4.  Mist and cover: 

Once you’ve got a good amount of seeds on your pad, lightly mist your seeds. Then, mist another tray until it’s suitably wet: this’ll act as the humidity dome on your seed-tray.

5. Mist every 12 hours: 

Mist your seed tray every 12 or so hours — this is all the water they need. 

6.  Uncover your tray: 

 Your microgreens should be about ready to lay bare after 4 or 5 days. Wait for the the baby leaves (cotyledons) to emerge and then give them another 24 hours. Ensure they remain out of light for about the first week for a durable crop.

7. Keep an eye out: 

Make sure your microgreens remain duly damp until it’s time to harvest. Pull up a corner of the grow pad every day, it should be wet to the touch — if not, mist until the pad’s saturated again. 

8. Time to harvest: 

Micro greens grown inside are usually ready to harvest in just two to four weeks (it can be longer in cold weather outside).

9. Clip, clip, clip: 

 Move your trays to a cool, shady place prior to clipping! They’re likely to wilt and go limp in the heat.

Harvesting Hydroponic Micro-Greens 

Keep things clipped and neat. 

You’ve got to be extra careful when you’re harvesting microgreens: leave a good clean portion of stem below the leaves, but be wary of cutting to close to the plant’s tender, growing base. Clean, sharp scissors only unless you’re growing on a larger scale, and then you may want to opt for electrical harvesters. 

Hydroponic Microgreens Kits

Building out of a box is way easier than spending an afternoon gluing tubing together. 

There’s a downside to hydroponics. 

Soil, for the most part, is pretty lenient — your crops may suffer on account of you getting a little heavy handed with the fertilizer, but the soil can act as a buffer and mitigate the worst of the damage. Not so with water. We recommend getting in touch with nearest hydroponics specialty shop where employees are likely to be able to help you along, or buying a book on the subject.

That’s where plug and play kits come in: they’ll tell you exactly what to add and do, and when! 

Here are a couple of our picks: 

HAMAMA Home Microgreens Growing Kit

This kit’s great for beginners looking for a smaller setup before they branch out. 

Hydroponic Microgreens Sectional Kit

No muss, no fuss with this compact step-by-step hydroponic microgreens growing kit!