The first official day of spring is just around the corner, but with snow still covering the ground, Mainers have to go indoors to start their spring planting.”It’s really to extend our season, we don’t have enough days to grow many plants effectively.” Says Gleason Gray, a professor at the University of Maine Cooperative Extention.To give your vegetables a good head start, you should let them germinate inside before transplanting them to your garden. But growing plants indoors takes more than just a green thumb.”The major factors are temperature, light, water, and the growing medium that you use to plant the seeds in.” Says Gray.He says a heating mat should be used to warm the soil to 70 degrees, growing lights should be put above the plants, and the best soil is a well-drained greenhouse mix. Once you have the right conditions, Gray says it’s just a matter of timing.”One of the earliest vegetable seedlings would be pepper plants which is 8 weeks before you plant it out, tomato plants are 6 weeks before you plant them out and then when you get to the vine crops it’s only 2 to 3 weeks.”He says the best time to plant vegetables outside is the end of May, so the earliest you should start planting inside is the beginning of April. He says it’s easy to see when a well-grown seedling is ready for transplant.”When it’s ready for transplant it will not be tall and streched, that means it’s had a enough light, it means it’s been grown at the right temperature, and it will have a good root system.”He says reading the back of the seed packages will help novice gardeners know how early to plant and what care is needed.For more information on growing seedlings indoors try these helpful links.â€¢University of Maine Cooperative Extension – free online newsletter for home gardeners. â€¢Marjorie Peronto, an educator with the University of Maine Cooperative Extension, has published a guide on starting seeds at home. â€¢University of Maine Cooperative Extension offers an extensive array of gardening information You can also call your local Extension office. In Penobscot County,the number is 800-287-1485 (in Maine) or 942-7396.