Reap an Early Harvest by Starting Seeds Indoors

Photo by Stephanie Griggs

Photo by Stephanie Griggs

Get a jump on gardening this year by starting seeds indoors for a wider selection of plants from which to choose, greater control over the quality of your plants and an earlier harvest. Transplanting your own seeds starts in the garden after the last spring freeze, which is also less expensive than purchasing young plants at a nursery — but only if healthy seedlings emerge, so you don’t end up buying both seeds and plant starts.

“Timing is everything,” claims gardening expert and former Bookcliff Gardens owner Dennis Hill. “While it’s not too soon to plan your garden, starting seeds too early will result in large, gangly, plants that won’t transplant well. A rule of thumb,” Hill continues, “is to count back six weeks from when you want to put plants in the ground.” (Check local frost dates). For example, if you expect to transplant tomatoes outside in mid- May, start your seeds indoors in early April.

Cold-hardy plants such as broccoli, cabbage and cauliflower can be direct-seeded outdoors in early February. Alternatively, start those cold-weather crops even earlier inside, like mid- January, for transplanting outside in March.

Hill recommends using a seedling mix to germinate seeds as opposed to soil from your garden. Regular potting soil will do, although a special seedling mix is preferred for a more uniform and designed germination. Starting seeds in individual cups will prevent fungus from spreading if one develops. You can buy new containers or recycle your plastic cups from last year after they’ve been sterilized. Wash and bleach them with one part bleach to nine parts water; rinse with plain water, then air dry.

To determine how deep to plant a seed, read the directions on your seed packet, or plant seeds two-thirds deeper than the diameter of the seed. Water your seeds lightly, though thoroughly, with tepid water.

Your seeds don’t need light during this stage, but they do require warmth. On top of the refrigerator, in the laundry room or near the water heater all provide the necessary heat for germination.

Once those seedlings start to emerge, they’ll still crave warmth, but will also need light at this point. Hill recommends investing in grow lights for gardeners serious about starting seeds indoors. The lights need to be close to the plants — 6 to 12 inches away. “They’re cheap, small, compact and work great,” Hill says.

Stacey Stecher, co-owner of Chelsea Nursery, a garden center in Clifton that specializes in native plants, grows herbs and veggies for her personal use. “If you want an heirloom tomato you probably want to start it yourself,” she advises. While you can find heirloom varieties in some seed catalogs, Stecher collects her own seeds from prior harvests.

When your seedlings are ready to transplant, you’ll need to “harden off” the young plants to prepare them for the outdoor climate. Seven to 10 days before transplanting, set the seedlings outdoors in a partly shaded area protected from wind for a few hours each day. Gradually increase exposure to full sun and wind each day. Be sure and keep the plants’ soil moist at all times during this period! Ideally, transplant on an overcast day or early in the morning to protect the seedling from the harsh sun. Soak the soil around the plant, and spread with a light layer of mulch. Happy gardening!

Originally published in the Spring 2020 issue of SPOKE+BLOSSOM.