Christa Bahner of Bahner Farm stands in the greenhouse the farm uses to grow many seedlings for their own use and to sell to customers. "It's baby season," she said of early spring.

This time of year, the greenhouse at the Bahner Farm in Belmont looks like a crazy quilt of seedlings, albeit one stitched together using only shades of tender green.

“It’s baby season,” Christa Bahner said, gesturing to the flats of tiny tomatoes, peppers, herbs, brassicas, flowers and more that fill the greenhouse.

Your living room probably won’t ever look like her greenhouse, but even gardeners who only have a sunny window can start seeds that will take root beautifully in their vegetable and flower gardens once the weather warms up.

Michelle Schraeder of Maple Knoll Farm in Solon is a Maine gardener who starts many seeds in a sunny window in her warm living room. She starts vegetables such as tomatoes, broccoli, cauliflower and onions inside her house before transplanting them to her large vegetable garden.

“Keeping the cats away from them is an obstacle,” Schrader said.

Transplanting seedlings instead of directly sowing seeds into your garden is particularly important for plants that are slow to mature or sensitive to frost, such as tomatoes, peppers, eggplants and melons, according to a bulletin from the University of Maine Cooperative Extension. Vegetables that are typically directly seeded in the garden include beans, beets, carrots, corn, peas, spinach, turnips and zucchini.

Extension gardening experts suggest using fresh seed from a reliable source, and using seeds saved from a previous year only if they have been stored in a cool, dry place. Seeds can be planted in any clean, two- to three 1/2-inch deep container with adequate drainage holes. Containers that were previously used for planting should be cleaned and disinfected with a solution of one part chlorine bleach to nine parts water, in order to help prevent disease.

Both Bahner and Schraeder recommends getting thrifty and crafty with containers for the seedlings. Schrader saves her plastic trays to reuse the following year, and also hunts for flower pots when she goes to the town dump. Bahner, too, said there’s no need to go out and buy new seed starting trays when it works just as well to save, wash and poke holes into the bottoms of food containers such as yogurt cups or cut-down milk cartons. Cardboard egg cartons also are a good, low-cost and biodegradable choice, Bahner said. Then, fill those containers with a high-quality soil.

“Generally, you want a good compost-based mix,” the farmer said. “Go to your garden center and ask the people who work there what they use.”

Cooperative extension gardeners do not recommend using soil from your garden to germinate seeds in containers, because it may contain weed seeds or diseases, and tends to dry out too quickly for fragile seedlings.

Home gardeners who are curious about making their own greenhouses or buying mini greenhouse containers should keep a few things in mind, Bahner said. If people want to make their own, she recommends buying proper greenhouse plastic from a greenhouse supply company because it lets in much more light than plain plastic wrap. And while store-bought mini greenhouses could definitely work well to start a few seedlings, people should keep an eye on them because they can overheat if placed in full sun, she said.

Once you have the containers and the soil, it’s time to plant. Gently press seeds onto the surface of the soil and follow the directions on the seed package about how much soil is needed to cover them. Seedlings may take from four to 12 weeks to mature enough to be safely transplanted into the garden. Bahner said the beginning of April is a good time to start lots of plants, including onions, brassicas such as kale, cabbage and broccoli, lettuce and slower-growing annual flowers such as marigolds, cosmos and nasturtiums. It’s also an OK time to start heat-loving varieties such as tomatoes, peppers and basil, which need eight to 10 weeks in the pots before being moved to the garden.

“If you start them now, they would go in your garden in early June,” Bahner said, adding that that’s probably just fine for the plants. “Things like basil will die below 45 degrees [Fahrenheit] anyway.”

When you have planted the seeds in your cups or trays, they need to be placed in a warm spot in your house to germinate, and then into a sunny and warm part of your house to grow. But even in the sunniest of windows, seedlings are likely to become tall and leggy as they stretch up to find more sun.

“I think the biggest challenges for home growers is to get a window with enough sun,” Bahner said. “Leggy plants can still do well, but I would not plant them without support.”

That support could be as simple as tying small seedlings to a stake make of a pencil or a chopstick, and larger seedlings to a small stick or a tree branch. The support should be at least as tall or taller than the plant, Bahner said. It’s also possible to “beef up” stringy seedlings when they’re inside by making sure there is some light air circulation coming at them. Gardeners could do this with a fan put on a low setting that is not placed too close to the seedlings.

“You don’t want them to flop over,” Bahner said.

The right amount of water is also necessary for growing sturdy seedlings. Many people have a tendency to over water their plants, but that can be problematic, the farmer said, sharing some tips about how to strike the right balance. At first, misting or spraying the seedlings with water can be a great way to maintain the right soil moisture. But if you’re going to be gone all day, it may not leave the soil wet enough to make it through the day, and in that case a watering can with a shower-like spout will work fine.

“You want the soil damp but not soaking,” Bahner said. “If you are not going to be home with them all day, water them well in the morning. Not at night, when it’s cool and dark, because that will promote fungal growth.”

And in a few weeks, when your seedlings have taken off, it can be really tempting to transplant too soon — but don’t rush it, Bahner and Schraeder both said.

“On a warm day in a few weeks, they could probably be outside for the day,” Schrader said, adding that at first she brings them in overnight.

This process is called “hardening off” and it can be critical to a plant’s ability to survive and thrive outside. Seedlings that have lived their whole lives inside should be slowly introduced to the elements. Waldo County garden expert Norma Rossel of Troy suggests the process should start about two weeks before you want to plant them in your garden, and includes reducing the amount you water the seedlings and gradually increasing their exposure to outdoor sunlight.

It’s a lot to think about — but Bahner has boiled it down to her top three most important things for gardeners to keep in mind.

“One: it needs more light. Two: don’t overwater. And three: don’t put it out too early,” she said, adding that home gardeners should not worry too much about getting it perfect. “The amazing thing about plants is that they want to grow so badly they’ll forgive all our mistakes.”

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