If you choose to plant your microgreens indoors, fill a small container with a few inches of organic potting mix. Plastic containers used for fruit, such as blueberries or strawberries, work well for this type of planting. Clamshell takeout containers will also work, as will aluminum pie trays — just be sure to poke some holes in the bottom so water can drain. Place a damp paper towel in first before the potting mix to prevent it from leaking out.
Using the same technique as you would for your outdoor microgreens, scatter the seeds ¼-inch apart and gently press them into the soil. Proceed to cover the seeds with ⅛ inch of potting mix. Mist the soil with enough water so it feels like a sponge.
Some growers recommend placing plastic wrap over the microgreens to promote germination. Place the microgreens on a south-side windowsill or another area of your house where it gets at least four hours of sunlight a day.