Starting Seeds Indoors

Our favorite growers, greenhouses or garden centers begin their growing schedule with some plants sometimes as early as January in order to have the plants sale-ready in spring. Every week thereafter the pace of seed starting increases dramatically with March and April as an absolute frenzy of activity. The growers have planned their plants for sale based on a variety of sales and marketing factors, but two very important considerations for them are space and energy requirements. When they place their seeds and cuttings order in the Fall, they’ve already calculated every plant’s general location in the greenhouse for growing and finishing, and accounted for light, temperature, water, and physical attention (handling) requirements. The wise home gardener will consider these same factors when planning their seed starting as well as their garden.

Working backwards in time from when you want to transplant outside in your garden, determine your seed starting date for each plant you’ve selected for your garden. It is helpful to input the last spring frost date (on average) in your gardening calendar because you will not want to transplant your tender vegetables or flowers outside before that date.  Once you’ve determined all your seed starting dates, you will need to make sure you have your supplies and space ready. 

Your seed starting mix is perhaps your most important supply and the one that is worth spending on. The germination period until the first few true leaves emerge, is when the plant you are starting indoors is most susceptible to diseases. Most plant diseases are soilborne, so it is only logical to use a quality soilless seed starting mixture with sphagnum peat moss, vermiculite and perlite. 

You’ll find many, many types of seed starting containers available and really anything with drainage holes will do a good job.  I’ve even poked holes in used egg cartons to use for seed starting, though I found it disintegrated too quickly for my liking. You’ll need a transparent plastic lid to help maintain proper temperature and moisture levels during germination, though plastic food wrap will work too.   My favorite seed starting container lately is the Jiffy Windowsill Greenhouse with Peat Pellets as the seed starting mix. 

Remember that proper temperature and moisture levels are most important for germination. Most flower and vegetable seeds germinate best when the temperature is 70 to 75 degrees Fahrenheit, so you will need your started seeds in a warm space until the seedlings have emerged.  When the seedlings are up, move them to a sunny window and protect them from drafts. If you don’t have a sunny spot, fluorescent lights placed 3 inches above the tops of the plants will help. They will do best with 12 to 16 hours of light a day.

Once the true leaves appear (after the first seed leaves), transplant your plant into a larger 4” container. This will prevent the roots from becoming cramped and will encourage stronger, sturdier stems. When transplanting, try to avoid handling the stem of the plant. Cradle the root ball and steady the plant by gently holding a leaf between your fingers. My grandmother always used a pair of kitchen spoons to handle the plant at the root ball. She would insert the spoons into the soil on either side of the plant and transfer the seedling to the new, larger container without even touching the leaves. To this day, I carefully inspect kitchen spoons before eating with them. 

Once you’ve moved your seedlings into the 4” containers, your only concerns will be ensuring they get enough water and light. About one week before your planned day for transplanting them outside, you will want to begin "hardening off".  A wagon is useful for this stage of bringing the plants in and out of the house. Place the :seedlings in an outdoor location that is protected from direct sunlight and wind for a couple of hours, bringing them back inside to a warm place at night. Increase their outdoor time over the week so that they will be strong and unlikely to suffer from transplant shock when you plant them in the soil outside. Thanks to your hard work and attention, your plants are in the best condition for success.