[header] How to grow kale indoors [title] Fill seed trays with a soil-less growing medium. [step] Purchase seeds trays for germination with drainage holes on the bottom. Fill each seed container in the tray with 3-4 inches of soil-less growing mix. 
Mist or sprinkle water over each container to moisten the mix. [substeps] Avoid using potting soil, which can clump up and hinder proper drainage of your plants.