Starting Vegetable Seeds Indoors

By Pat Cook, Master Gardener, SCMG

It’s getting to be that time of year when I long to start my vegetable garden.

I’m sure my neighbours wonder why there is a bright glow coming from the spare room along the side of my house.  The lights go on and off at exactly the same time every day.  Well, I can explain, that room has been converted into a greenhouse where I start my seedlings for the upcoming growing season.  I start tomatoes, peppers, onions, beans, cucumbers, many different herbs and some flowers indoors every year.

Starting seeds indoors allows me to get a head start on the growing season.  It’s a very economical way to have a vegetable garden.  A package of seeds can range from 99¢ to $6.00 a pack depending on the variety.  Sometimes there are as many as 200 seeds in a pack.  What a deal!

I have started seeds inside my house for the past 10 years.  I admit it – I might go a little overboard with how many seeds I start, but I never, ever throw any seedlings away.  I keep a journal recording my garden successes and failures so that I can refer to my notes from previous years.  Each year I seem to need more seeding trays, more shelving and more grow lights.

Starting seeds indoors allows me to take the time to select varieties that will grow best in my hardiness zone (5a).  I find a much bigger selection in seed catalogues then I would find at the local garden center.  To save more money I also use seeds that I have harvested from my own garden or I participate in seed exchanges.  I always make sure to check with my local garden club to see if they have a seed exchange coming up.  I’ll watch for upcoming Seedy Saturdays in the spring – there is always a huge selection of seeds and tons of information about starting seeds indoors.

Sowing seeds indoors gives seedlings a chance to grow in a stable, controlled environment.  Outdoors, the unpredictability of rain, drought, low and high temperatures, sunlight and pests can take a toll on young plants, especially when they are just getting started.  Indoors you can control these elements to maximize growth and give your plants the best shot at thriving when they are finally transplanted outdoors.


General Tips for Starting Seeds Indoors:


  • As a general rule, most seeds should be sown indoors about 6-8 weeks before the last frost in your area.
  • Make a list of what you would like to grow. Be sure to plant extra seeds because not all seeds will successfully germinate.  Plant a few seeds in each cell and prune out additional seedlings once they have germinated.
  • Use a good quality potting or seeding mix, not garden soil. Garden soil comes with many pathogens that might inhibit the germination of new seedlings.
  • Start your seedlings in small cell packs and pot them up into larger sized containers as they get bigger. All containers should have good drainage.
  • The biggest challenge of growing seedlings indoors is low light. Sunny windows do not usually provide enough light for healthy, stocky plants.  I always recommend some type of supplemental lighting; either a plant light or a full spectrum fluorescent light. My favourite grow light is a fluorescent T5 which provides a full spectrum of light for the tiny seedlings to get a good start in life.
  • Don’t place your plants so close to the window that they are subjected to drafts or close to a heat source that could dry them out.
  • Label your seed starts. The more plants you start from seed the more important careful labelling is.  It is painfully easy to lose track of which pepper is which.  Plant labelling allows you to correctly identify seedlings before they are recognizable.

Starting seeds indoors isn’t as easy as setting a pot in the window, but you don’t need a greenhouse to make them grow either.  Follow the directions on the seed packet and you should be on your way to successful seed starting.