Attention gardeners—or green-thumb wannabes! March is the month to start seeds indoors so your plants will be ready to transplant outside once the warm weather arrives and the soil has warmed. For annuals and vegetables, this can be as soon as the threat of frost has passed. According to the University of New Hampshire Cooperative Extension website, the final frost date in Hanover falls anywhere between May 10 and June 10.

Seed packets will tell you what the average outdoor temperature needs to be for each kind of plant to thrive. Once you decide what you want to grow, grab a calendar and start counting. Most vegetable and flower varieties take six to ten weeks to germinate from a seed and grow into a plant that’s ready for the great outdoors.

 

The tools you need to get started include containers as least two inches deep with drainage holes. Garden centers such as Longacres Nursery Center in Lebanon and Hanover True Value Hardware stock plastic cell packs and growing flats for this purpose. These containers are reusable, so when the seedlings have settled into their new digs, wash and save them for next year. Another choice is peat pots, which can be planted directly in the ground. 

You will also need commercial seed-starting soil or soil-less potting mix. A grow light with wide-spectrum florescent bulbs made for plant growth is also good to have, and of course, you’ll need seeds.

Fill the containers with the soil and moisten. Add the seeds, and then cover with a thin layer of soil. Mist the top with a spray bottle to moisten the top soil without flooding the seed with water. Cover the tray with plastic wrap or the plastic cover that comes with some trays to keep in the warmth and moisture.

Place the tray of seeds under the grow light hanging about two inches above the surface. Keep the light on all day and night until the seeds sprout. Then remove the plastic cover and keep under the light for at least 16 hours a day, raising the light as the plants grow. (A timer for the light will keep you from having to remember to turn it on and off.)

It’s possible to start seeds without a grow light. You will need a sunny, warm window with light coming through most of the day. The benefit of a grow light is it keeps the new seedlings from becoming too long and spindly as they try to reach for the sunlight.

Before you can place the new plants into the ground, they need to go through a process called hardening off. This helps them adjust to colder temperatures, wind, and sun by toughing-up their stems and leaves. Take the plants outside for longer periods of time each day. Eventually, when the weatherman says it’s safe, you can leave them outside all day and night. Then they are ready to go into the ground. If a cold spell comes along, cover the little plants with upturned empty pots, buckets, or other covers. Just be sure to remove them as soon as the day heats up following a chilly night.