When our days start to get longer, spring is around the corner, I know it is time to prepare for the upcoming growing season. In planning the spring garden, whether annual, vegetable or perennial, one of the most exciting tasks is seed planning; a crucial step to ensure a successful and bountiful harvest. Whether you’re a seasoned gardener or just starting out, understanding the timing of seed starting is essential for maximizing your garden or balcony’s potential.

One of the biggest questions we get in store is, “How do I know what seeds to start when?” To answer this question, you need to know one crucial thing (two if you are starting vegetables). Figure out when the last frost date in your local area and count backwards. When starting your vegetable seeds, you should also know the number of days to harvest. According to the Farmer’s Almanac, the last frost date for 2024 in the Guelph area is approximately May 13. By counting back from this date, we pinpoint the optimal times to start various seeds;
- 12 weeks before the last frost (February 20): Start seeds for rosemary and leeks
- 10 weeks before the last frost (March 5): Start seeds for parsley and peppers
- 8 weeks before the last frost (March 19): Start seeds for broccoli, cauliflower, and cabbage
- 6 weeks before the last frost (April 2): Begin seeds for tomatoes, eggplants, and peppers
- 4 weeks before the last frost (April 16): Transplant the cold hardy crops such as collards and leeks outdoors.
By following this timeline, you ensure your seedlings are ready to be transplanted into the garden at the optimal time to give them an opportunity to thrive and produce a fruitful harvest.
Knowing the number of days to harvest (find this on the back of the vegetable seed package) means you know the approximate time between planting and when your food is ready to eat. Plotting the days to harvest on a calendar will also allow you to plan for two harvests out of the same space.

What can I sow now?
Now is the perfect time to start seeds for Impatiens & Geraniums. OSC has some fantastic options this year with a variety of popular flowers in an array of colours (available in-store and online). We have also noticed a surge in interest for onions and leeks, as gardeners take advantage of the opportunity to start these crops indoors. For those of you who are up for a challenge, now is the time to start seeds for asparagus, which requires patience but rewards diligent gardeners with a delicious harvest for years to come.
Equipment to get you started
Seedlings are like baby plants, and how you care for them early on makes a big difference in their growth. At Royal City Nursery, we advise on a few basic but essential things to get you going;
- Seed starting tray with cell inserts and a plastic dome or lid
- A gro lamp
- Heat Mat
- Soilless Media such as Pro-Mix or Beats Peat Coconut Coir
- Labels
- Evolve’s Organic Seedling Starter Fertilizer

While it’s possible to start seeds without these items, cutting corners now may affect the quality of your plants later on. Stop by Royal City Nursery to pick up your seeds, seed starting supplies and chat with our knowledgeable staff. Be sure to follow us on socials (@royalcitynursery) too for lots of informative, fun and inspiring seed-growing content this spring.