top of page

What Seeds to Start Indoors and What to Direct Sow

Updated: Jun 1, 2023

Not all seeds benefit from being started indoors. Some vegetable seeds do better planted directly into your garden and do not hold up well to being transplanted. Other vegetables grow so quickly that it is not worth the space or effort to start the seeds indoors. Many flower seeds, on the other hand, take longer to grow and benefit from the head start of being seeded indoors in the weeks prior to your last spring frost.

Here is a list of what seeds to start indoors and what to direct sow outdoors in growing zones 2 - 4 of Canada or other similar cool gardening climates.

A chart showing what vegetable seeds to start indoors and what seeds to plant directly into your garden in zone 3 Calgary and Edmonton, Alberta.

What Vegetable Seeds to Start Indoors

These vegetable seeds have longer days to maturity (find this information on your seed package) and benefit from being started indoors or being purchased from a gardening center already started. If you wish to start your own seeds check out When To Start Seeds Indoors for a printable guide with suggested seeding dates for these vegetables along with common flowers.

  • Asparagus (perennial plant that takes 3 years until first harvest)

  • Broccoli

  • Brussel Sprouts

  • Cabbage

  • Celery

  • Cucumbers (can be started indoor or out)

  • Leeks

  • Melons

  • Onions (if growing from seeds not bulbs)

  • Peppers

  • Squash (can be started indoors or out)

  • Tomatoes

Most herbs (besides dill) benefit from being started indoors. Peppermint is a perennial and will come back year after year. Take note, peppermint can be invasive in you are not careful to keep it in check.

What Vegetable Seeds to Direct Sow

Plant these vegetable seeds directly into your garden. There is no need to start these quick growing seeds indoors. Root vegetables (ie. carrots, beets, potatoes) do not like to be transplanted and you will stunt their growth and actually harm them if you attempt to transplant your root crops. To find out when to plant these vegetable seeds in your garden in zone 3 Alberta read When to Plant Your Garden.

Harden off Seedlings Started Indoors

If you are starting seeds indoors, make sure you harden them off prior to transplanting into your garden to prevent transplant shock.

Plant squash and cucumbers in biodegradable pots to minimize root disturbance during transplant, as disturbing the roots of these plants can cause them to go into transplant shock and may take weeks for them to recover. When transplanting squash and cucumbers, remove the bottom of the biodegradable pot, leaving the remainder of the pot intact.

If you have found this article helpful and would like to see more gardening tips and tricks, subscribe to my blog (the bottom of the home page) and follow me on Pinterest, Instagram, Facebook and/or YouTube!

Find out what vegetable seeds should be started indoors and what seeds to plant directly into your garden in zone 3 Calgary and Edmonton Alberta Canada.


Related Posts

See All


Great information!

The only thing that never worked for me in your "plant outside" list is beans. Then again, I am in zone 2b and our soil stays cold for a long time and cool over the summer too so my beans never germinated very good in the cold soil. Few years back I tried starting my beans indoors (I know they don't like their roots disturbed) in 4 inch pots. I have a 100% germination rate now and I am able to carefully transplant them from the pots in early June (some of them start running by then), and I am able to harvest lots of green beans as well as snap beans.

Krista Green
Krista Green
Mar 10, 2021
Replying to

Good point about the soil temperature. Beans I plant on their own in the middle of June. They are last to go into the garden. I find by then it is warm enough they grow so quickly!

bottom of page