I planted a tray of broccoli seeds six days ago and we harvested our broccoli microgreens into the salad that we had for dinner this evening.
Last week I laid out a few paper towels on a clean reused plastic food container. There is no dirt involved in this approach. I then covered the towels with seeds that I had previously soaked for about 5 hours. (I bought the pack of 10,000 seeds for $5.50 through Amazon and probably used only 20% of them with this planting.)
I then misted the seeds with a spray of hydrogen peroxide (less than $1 at Walmart) to kill off any pathogens that might have attached themselves to the seeds along the way. After the one time application of hydrogen peroxide I misted the spread of seeds on the towels with water -- but not so much as to soak the towels. I just wanted to keep them mildly damp.
I then covered the container so that the seeds were in darkness and continued to mist every 5 or 6 hours. Because the humidity is so low here in the Arizona desert, extensive misting is necessary. People living in more humid places might be able to mist just a few times a day.
After two days the seeds had started to sprout and I removed the dark covering. I then left the tray out in the open, uncovered, and throughout the days continued to mist with water as before. I have added nothing to the water -- no nutrients or fertilizer. And while the tray is sitting next to some plants with grow lights over them, the broccoli is only benefiting from that indirectly. Most of the light is natural sunlight coming in through the window.
Harvesting requires a pair of sharp scissors.
This is a really inexpensive and simple way to add some nutritious and tasty greens to the diet. I'm told that the microgreens are more nutritious than if I were to plant in the soil and allow the plants to mature. But I don't know if that is true.
The lettuce in our salad tonight was also grown indoors using a counter-top Miracle-Gro aeroponic growing system. The jury is still out on the Miracle-Gro system but the microgreens on a paper towel worked great. Both the broccoli and lettuce tasted good. (I have not yet been able to get any of the leafy plants started in the outdoor garden for the winter. The heat still lingers here in the upper 90's. And we're over halfway through October!)
More experimentation ahead.