Back a while ago, The Farmer found this book by Peter Burke in his local library and took a long gander. (Here is the link to the local library. The author also has a website with supplies and an outline of his method.)
Year-Round Indoor Salad Gardening: How to Grow Nutrient-Dense, Soil-Sprouted Greens in Less Than 10 days
In the book, Mr. Burke shows a simple way to grow sprouts on soil, without the need for grow lights or other expensive equipment.
This is The Farmer’s second winter using the method, and here is what it looks like for him.
Using pea seeds produced on the farm, about 1/4 cup of seeds are soaked for 24 hours. This makes them swell up and germinate faster. (The Farmer will often do this before planting pea seeds outside in the spring as well.)
The Farmer takes the top of a Styrofoam egg carton, fills it with well-moistened potting soil, and spreads the seeds on top of the soil. This is then covered with a sopping wet paper towel to prevent the seeds from drying out.
The seed-laden container is then put in a warm, dark place for several days. In The Farmer’s house, this is on the top shelf of a closet near a heat vent, with a black garbage bag over the top.
Here are three containers pulled from their hiding spot showing how the seeds germinate in the dark and the plants begin growing.
The plants grow tall in the dark, looking for sunlight. In a few days they are an inch-and-a-half high or so. Then it is time to take them out and green them up for a few more days on a ledge or table near a sunny window. They will probably need a watering or two at this stage. (Mr. Burke says to water daily. The Farmer’s watering scheme is less predictable.)
When you think they are ready (for peas, when the leaves have opened), simply cut at the base, throw in your salad, and enjoy!