Kale microgreens are some of the faster and easier to grow micros out there, making them a great starter crop for beginners. It’s hard to mess these up! They perform equally well hydroponically or in soil. However, if you are harvesting them past the 10 day mark I would recommend either growing in soil or supplementing your hydroponic media with some nutrients.
The cultivar that I prefer to grow is Red Russian Kale, mostly due to the beautiful coloration on the stem — a light, pinkish-red hue that paints a stark contrast with the green leaves. It’s a affordable seed to get as well.
Everything you need to grow kale microgreens.
Most of what you need to grow kale microgreens you can find around your house. Aside from the seeds, of course. I like to buy in bulk because I grow commercially, but you can use seed packages found at the local garden store if you want. Otherwise, look to a reputable seed company online (like Everwilde Farms, where I buy my seed).
Fill your container just below the brim with soil, mist it, and pat it down slightly. Don’t compact the soil too much or the roots will have a rough time digging in. As mentioned above, you can grow these hydroponically as well, but I prefer soil for flavor reasons.
If growing in a 10×20 tray, use around 1-1.25oz of seed for the tray, doing your best to distribute as even as possible. I use an old spice shaker to get a good distribution, but you can do well with your hands or a simple glass too.
After planting, lightly mist the seeds once more and cover them with something that will keep out all light. I grow in 10×20 plant propagation trays, so I like to use another 10×20 tray flipped upside down. But as long as you keep it dark, anything will work.
Over the next few days, check in on your kale pickups to make sure they’re germinating and to mist them lightly with water. You should see most of your seeds germinate within 3 days – if not, something went wrong (usually temperature or bad seed).
After 3-4 days, your microphones are ready for the sun. At this point, you have the option of putting something on top of your container to press down on the young seedlings to stress them a bit before putting out in the sun. People do this to force the plant to struggle, meaning a larger, more healthy plant.
For the next week or so, be sure to water your plants regularly – but don’t overdo it, especially in the middle of the tray. That’s an easy way to get mold or fungus. The amount you have to water will depend on two things:
Are you growing with sunlight or artificial light? You’ll have to water more if growing in the sun.
How deep is your growing medium? You’ll have to water less the deeper it is.
Around ten days after planting your kale microgreens should be ready to harvest. You can let them grow longer and pass into the true leaf stage, where they straddle the line between microgreens and baby greens, but that’s up to you.
When harvesting, it’s important to use a technique that avoids the need to wash your greens. Washing greens will dramatically reduce their shelf life as well as waste a lot of your time. Provided you’ve grown in a clean, safe environment and you harvest in a way that avoids debris, you can completely skip washing your greens.