I cannot think of a better way to feel a sense that spring is arriving soon then to start some vegetable seeds indoors to get a jump on the spring gardening season.
If you are looking to grow your own vegetables, here are some seed starting tips.
Starting seeds indoors can give you a jumpstart on the season, but starting too early may leave you with spindly overgrown transplants. The ideal number of weeks from seeding to setting out in the garden is as follows for several common crops.
8 to 12 weeks: celery, leeks, onion
6 to 8 weeks: eggplant, pepper, tomato
4 to 6 weeks: basil, broccoli, cabbage
3 to 4 weeks: cucumber, lettuce, squash
To determine when you should plant your seeds indoors, count backwards the number of weeks indicated, starting with the date on which you plan to transplant your seedlings to the garden.
Tender vegetable plants should not be set outdoors until the danger of frost has is past. Memorial Day is usually a safe time to plant warm weather crops outdoors in central New Hampshire.
Warm weather crops include peppers, eggplant, tomatoes, melons, and squash, among others. Cool season crops such as spinach, cabbage, brussels sprouts, lettuce and kale grow best in cooler soil and may be planted outside as early as mid-April
Start with a sterile soil-less potting mix. Any type of container can be used as long as it has drainage holes and room for the roots to grow. Some folks like to wet their soil-less mix with warm water prior to filling their containers; others prefer to fill with dry soil to just below the rim and then wet the mix. Either method works.
Seed packets contain useful information such as how deep to plant the seed, days to germination and the recommended temperature. Check the seed packet to see if the seed can be started indoors, or if it should be direct-sown outdoors. Some plants, such as carrots, beets and peas, do not transplant well and grow best when sown directly into the garden. Some, such as tomatoes, peppers and watermelon need warm soil to germinate. Using a heat mat will keep a constant soil temperature of 80 degrees. Once the seeds have germinated, they should be grown at cooler temperatures of about 65 to 75 degrees.
A pair of needle nose tweezers comes in handy to grab a seed and plant it precisely where you want it in the container. After seeding, water the seed in lightly with lukewarm water. It is important to not let the soil dry out during germination, but equally important not to over water.
Seedlings need lots of bright light as soon as they germinate. Natural sunlight, even through a bright, sunny, south-facing window, does not provide enough direct light, and seedlings can get “leggy” as they stretch to reach the sun. Hanging full-spectrum fluorescent bulbs an inch or two above your seedlings and providing them with at least 10 hours of light a day will help keep your seedlings compact and strong. As your seedlings grow, raise the lights to keep them just above the tops of your plants.
By following these steps, you should have strong, healthy vegetable transplants ready to go into the garden when spring arrives and the frosts have gone.
(Ann LaCroix is a UNH Cooperative Extension master gardener.)