Here in Connecticut, mid March is the time to plant tomato seeds indoors.I have just planted this tray, and covered it with plastic wrap to keep in the moisture, because the air in our house is dry. The tray needs to be kept warm, and heat from underneath is best. As soon as they can be seen peeking through the soil, the cover will come off, and I will have to keep them moist, but not saturated with water. They will need sunlight or grow lights in our cloudy New England weather too.