Updated: Oct 30, 2019
Starting seeds and growing your own seedlings is not as hard as you may think, and there are benefits to starting your own seeds.
The selection of seeds is much larger than the selection of bedding plants, giving you the option of growing exactly what you want. Heirloom varieties, short season crops, novelty types, organic, are all choices you can make when looking for seeds. There are hundreds of different varieties of seeds available in the seed rack giving the gardener lots of options! Growing your own seedlings can also be cost effective. A packet of seeds can produce hundreds of plants for a very small price, whereas bedding plants are more costly.
“Some seeds can be directly sown into the garden in May but there are others seed varieties that require a longer growing season..."
Some seeds can be directly sown into the garden in May but there are others seed varieties that require a longer growing season and these should be started indoors and then planted outdoors. Most flowers, and some vegetables such as peppers, tomatoes, eggplant, onions, celery, and leeks can be started in March. Other vegetables such as cabbage, cauliflower, broccoli, brussels sprouts, kale, corn, cucumber, lettuce, squash, zucchini can be started indoors throughout April to get a head start on the season.
When starting seeds indoors, gather your materials before starting. You will need containers (plastic or peat), a tray to put the containers in, a clear dome to place over the tray, and sterile starter mix. A heat mat is useful as seeds germinate faster with bottom heat, and an adjustable light stand to provide additional light to grow strong healthy plants. If you are re-using material from previous years, it is very important to clean everything first with a mild bleach solution, to prevent any disease, or pests.
Start planting seeds by first filling the containers almost to the top with a moistened starter mix. Sprinkle the seeds in the container and then cover them slightly with the starter mix. How many seeds per container and spacing depends on the container and the seeds. If you are using peat pellets or peat pots, 2 seeds per pellet/pot is enough. Once the seeds are planted, place the container filled tray on a heat mat and put the clear plastic dome over top. It is important to keep the soil moist but not wet. Once the seeds have germinated, remove the plastic dome, to allow for good air circulation, and the heat mat, to slow down the growth, creating strong, stocky plants.
Lots of direct light is very important in growing healthy seedlings. A south-facing window works well, or an adjustable light stand placed 15-20 cm above the seedlings is ideal. To help ensure a good root system, first fertilize the seedlings with 10-52-10, and then switch to 20-20-20. When the seedlings have formed their first set of true leaves, they can be thinned out or transplanted into individual containers.
Before placing young plants outdoors, harden them off first, by placing them outdoors during the day and bringing them in at night. Some plants such as tomatoes, peppers, squash, cucumbers, corn, etc., cannot tolerate any frost, so do not place them outdoors until all threat of frost has passed.