You can grow microgreens with water, though you will require additional materials such as a growing mat and light source. If growing microgreens with just water, it’s imperative that you select quality water that is chlorine-free, and carefully maintain the optimum moisture level for your plants.
Continue reading to discover how to grow microgreens without soil, how much water they require, and which material is best for your growing mat. Also, get the answer to all your troubleshooting questions and learn how to manage mold outbreaks or wilting.
Can You Grow Microgreens Without Soil?
While potting mix is a great medium to produce healthy plants, it is possible to grow microgreens without soil, which may be ideal for you if you lack space or want to avoid mess.
What Do I Need To Grow Microgreens Without Soil?
Hydroponic microgreens require a growing mat or pad made from jute or wood fibers that allow microgreens to grow on them. Additionally, you will need:
- Microgreen seeds.
- Two trays: one to hold the growing tray and another to use as a cover.
- Growing tray to hold your microgreens. This tray should have holes in the bottom.
- Spray mist bottle.
- pH test kit.
If you don’t have a sunny indoor area available, you may also want to buy an LED or fluorescent light.
Can You Grow Microgreens Without Sunlight?
Microgreens require around four hours of direct sunlight per day to thrive. This can increase during the winter months, and thin, pale plants signify light deficiency.
It is possible to grow microgreens without sunlight as long as you provide them with an alternative light source.
LEDs are easy to source, inexpensive, produce minimal heat, and provide sufficient lighting for the growth of microgreens. However, the bulbs may not have adequate protection from dust and water, which means they are susceptible to damage.
Fluorescent lights provide a similar amount of light but require more power to run. If using fluorescent lights, opt for a mercury-free variety where possible, as mercury can contaminate your microgreens if the bulb is damaged.
You should ideally keep microgreens at a cooler temperature of between 60 to 70 degrees Fahrenheit. However, warmer temperatures can inspire faster growth, so find what works best for your plants. In general, sufficient light is more critical than temperature.
How Can I Grow Microgreens At Home Without Soil?
- Take one of your solid trays and add around a cup of water (for a standard 10×20 tray)
- Place your growing tray inside the solid tray.
- Add a growing mat or pad to your growing tray and allow it to soak up the water. The surface area of the mat should have full coverage of water.
- Densely plant your seeds so that they cover the surface area of your mat without overlapping the seeds.
- Cover with your remaining tray to maintain optimum humidity and create the blacked-out environment that the seeds require to germinate.
Lightly mist your seeds for roughly 12 hours, ensuring they stay damp without becoming saturated.
Which Microgreens Grow Best Hydroponically?
Many microgreens grow well hydroponically, including broccoli, radish, basil, kale, chia, curly cress, turnip, and amaranth.
What Kind Of Water Do You Use For Microgreens?
Because hydroponics relies on water to grow your microgreens, its quality is essential. The best forms of water are rainwater or distilled water.
Regularly test the pH of your water, which should sit around six and can affect your plants’ health and growth if imbalanced.
If you need to increase the pH range, try adding wood ash, lime, or baking soda to the water. If you need to lower the pH, add a dash of vinegar, lemon, or acid.
Can You Use Tap Water For Microgreens?
You can use tap water to grow your microgreens, but it’s best to boil or sit for 24 hours to remove the chlorine.
Are Hydroponic Microgreens Safe?
Hydroponic microgreens are safe as long as you take the proper food safety precautions. Ensure that you sterilize your trays, use quality water and wash your hands thoroughly before handling your plants.
If your microgreens are infected by fungus or begin to rot, discard the entire pad and growing tray. Ensure that you thoroughly clean your solid tray with vinegar or a weak bleach solution.
Can You Grow Microgreens On A Mat?
There are several mediums you can use for growing microgreens without soil. These mediums are known as substrates and can be used to support the roots within your hydroponic system.
Common mediums for growing include coconut coir, burlap, hemp mats, and vermiculite.
Coir is an excellent growth material as it holds water well but allows excess moisture to run out of it. Coir is cheaper than soil, so a great option if you’re on a budget.
While burlap is one of the cheapest growing materials, it can provide a real challenge for growing your microgreens. While experienced growers can produce similar results to microgreens grown in soil, it takes a lot of trial and error and is not a suitable material for beginners to use.
The design of hemp mats allows them to evenly transport water around your microgreens while keeping the water and air ratios optimized for the plant’s roots. The main problem with hemp is that it’s flimsy and easy to damage.
Vermicule is a mineral that expands when heated. Its pH is neutral, and it is sterile and mold resistant. It’s great for water retention and contributes small amounts of potassium and magnesium to your greens.
Are Microgreen Mats Reusable?
You can reuse a mat if you’re growing microgreens in small quantities for yourself. However, if you are growing microgreens commercially, it’s not feasible to continue regrowing multiple batches on one pad.
What Happens If You Overwater Microgreens?
Rotting plants can be a sign of overwatering. The roots of your plants require oxygen, so if they are completely submerged and aren’t getting enough oxygen, they can become susceptible to root diseases or die. The best way to rectify this is by utilizing an air pump to circulate oxygen through your water.
Conversely, if your microgreens are wilting, they may have a deficiency of water. Growing plants through hydroponics require a delicate watering balance, and your grow pad should remain soggy, like a wet sponge.
Hi, I’m John Stephens, chief editor and writer for Totalgardener.com. I’ve been gardening and raising animals for over 15 years starting with a small backyard plot in Northern Virginia where I grew corn, potatoes, squash, and using a high mulch technique called the Ruth Stout Method. I also raised ducks and small mammals for meat and eggs in a movable pen similar to the ones used by Joel Salatin. I later moved to Colorado where I experimented with growing greens using aquaponics inside. I eventually added a microgreens setup and home sprouting operation. I’m excited to share everything I’ve learned plus more from the other local gardening and animal raising experts I know.