Laura Mathews is a garden writer and photographer. She is fascinated with sustainable farming and local food. Once in a while, she hangs out with new-ish gardeners and helps them as a garden coach. Visit

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Starting Seeds Now
by Laura Mathews    

By March, we’ve dog-eared our seed catalogs and sense that the germination of the growing season is upon us. We’ve carefully ordered (or bought at the garden center) the seeds we will nurture from seedling into fruit. Decorated packets that rattle and hiss a bit as we jostle and inspect them, have landed at our doorstep. We hope for a future with healthy ‘Lipstick’ pepper plants, lush vines of ‘Green Zebra’ tomatoes, and tall, robust Thai basil. Even now, while we still may have snow and frigid temperatures, we can affect the positive outcome of August’s garden with certain good seed starting practices.

Germination is a natural process that can succeed when executed in several different ways. The combination of soil, water and light will get you very far if the needs of the plants are met. For the best luck, however, there are a few steps to take that might not be intuitive but will definitely help ensure the success of your seedlings.

To start, you’ll need containers to hold sterile soil while allowing water to drain. If you’re interested in saving resources and money, any shallow vessel that allows small holes to be poked in the bottom and soil to be held, can be used to start seed. I’ve found that plastic food take out containers with clear tops are excellent for starting seed. They are small enough that you can start a different variety in each and the clear tops serve wonderfully to create an environment that holds in moisture and heat while allowing light in for early seedling growth.

Once you have your containers, choose your soil. There are different approaches to soil selection for seed starting. But just starting out, I would recommend a sterile medium. You can use anything from coir to a traditional sterile potting medium. I’ve had good luck with various mixes of sterile compost and coir. Make sure to thoroughly soak the soil you choose either before filling the container, but certainly before placing the seed into the soil.

Eggplant seedlings.

Keep in mind, that it’s important to start different seeds at different times. You’ll want to start seeds that have longer days to maturity — like tomatoes, peppers, eggplants or some long producers like herbs — now. It’s also a good time to start cool-season vegetables like the brassicas, kales and Swiss chard. There are some things that really don’t need to be started inside because either they transplant poorly or have such robust growth in the garden that inside starting is a waste of energy. Squash, radish, beans, and peas are best directly seeded.

While my next suggestion may sound like a stupid thing to point out, I’ve encountered even very talented plant people who didn’t do this (but were way happier once they began to do it). Before starting your seed, read the information on the seed packet! The packets will often tell you how many days to grow inside before transplant, which will allow you to plan when to start your seeds based on last frost information. They will tell you how deep to plant your seeds and cite days until germination. If the seed packet doesn’t provide much info, look for more at university or agricultural extension websites online.

Once your seeds are added to the medium at the right time and right depth, a couple of important things that aren’t intuitive come into play. Many seeds will benefit from warm soil temperatures for better germination speed and rates. Seed-starting mats that gently heat the soil are available. If the cost is prohibitive, consider sporadically using electric blankets or heating pads. Monitor the heat closely. Soil temps above about 80 F are undesirable. Baked seed is a bummer.

Using a watering can is not the best practice for seed starting. The force of the water can push your seeds deeper into the ground and upset placement. Even after germination, watering can damage plants. Once sprouted, forceful water can bend the seedlings down and embed them into the soil. Early in the process, cover the seeds and seedlings with something clear to hold in water but allow light, and only gingerly add water with a spray bottle.

Seeds sprout under cover.

Sprouts emerge from the soil mix.

Another seed-starting process that feels a bit odd at first is placing the light source close enough to the sprouting plant. If you’re using shop light fixtures with fluorescent light bulbs — a good and inexpensive option — hang them above the plants with either chain or rope so you can adjust the position of the light as the seedlings grow. Your plants will get enough light to thrive if the light source is nearly touching the seedlings. Plants will also benefit from a longer exposure to light than window light affords. Literature will tell you to give your plants about 8 hours of artificial light a day. I tend to lean toward 12 hours. I also rotate my trays to give all the seedlings equal access to light and to keep them from bending toward the stronger light. The bottom line is, if light is far away, the plants will stretch to reach it and you will have leggy seedlings with weak main stems and they won’t do as well in the garden.

Circulating the air is important to growing seedlings with strong center stems while protecting them from fungal issues. You can use a fan in the growing area to do this. Once the seedlings get their first true set of leaves, remove any covering that is touching the seedlings or preventing the light source from being close enough. To start, use the fan at the lowest setting and place it far away from the seedlings. The gentle airflow mimics wind while gently drying the seedlings and top of the soil to lessen the ability for fungus to make a home in your seed trays. As the plants grow, increase the speed of the fan to increase the exposure to the airflow. The breeze will encourage the seedlings to develop thick stems that will help them stand up to the wind and pounding rain.

I’m an organic gardener, so I only use weak compost teas applied via spray bottle on my seedlings. But if you don’t walk the organic path, be sure to only use a weak concentration of chemical fertilizers to your seedlings. Too much fertilizer of any kind can easily burn delicate seedlings.

As the plants grow, you’ll need to thin them out to provide space to grow. I use scissors for this. Pulling up on a seedling can upset the roots of other nearby seedlings. Once the plants become large and the roots begin to need more space, transplant the best ones into their own small pot. Keep in mind how many plants you can really use in your garden and how many you can give to friends.

Tomatoes seedlings in pots.

As the time nears to transplant, it’s important to harden off your plants. This is a process of gradually exposing your plants to the weather and sun. Start with as little as 1 hour outdoors and increase the time daily. Begin 10 to 15 days before it is time to transplant (again, check the dates of the last frost in your area).

While all these steps may seem like a lot of work, growing your own seedlings has many advantages. If you purchase seed, you have access to many different types of vegetables and varieties that you won’t find at your local garden center. You also know exactly where your plants have been and how they’ve been raised. It’s also fun for children — and grownups, frankly — to watch as a tiny seed becomes a sturdy plant. 

Photos courtesy of Laura Mathews.


Posted: 03/06/13   RSS | Print


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