What growing zone is St. Catharines, ON?

St. Catharines is in growing zone 7a, with a frost-free growing season of roughly 218 days between the average last spring frost and first fall frost.

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Last Frost Date for St. Catharines, ON

Q: When is the last frost in St. Catharines, ON?

The average last spring frost in St. Catharines, ON falls around April 7, based on historical Environment Canada frost data. Actual dates vary by a couple of weeks year to year, so treat it as a planning guide, not a guarantee.

Ontario · Growing Zone 7a

Last Spring Frost

April 7

First Fall Frost

November 11

Growing Season

218 days

Hardiness Zone

Gardeners in St. Catharines, ON can expect the average last spring frost around April 7, and the first fall frost around November 11, based on historical Environment Canada frost data for the area. That gives St. Catharines a frost-free growing season of roughly 218 days. Actual frost dates shift by a week or two year to year, so use this as a planning baseline rather than an exact guarantee, and always check your local forecast before moving tender plants outside.

You have your St. Catharines frost dates. Now put them to work: GrowBlock counts back your indoor seed-starting weeks, marks your safe planting day, warns you before a frost, and lays your whole season out on one timeline.

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What this means for planning

Most warm-season crops (tomatoes, peppers, squash) need transplanting only after the last frost has passed, and are usually started indoors 6 to 8 weeks before that date. Cold-hardy crops (peas, lettuce, spinach) can often go in the ground a few weeks before the last frost. As St. Catharines's first fall frost approaches in November, it's time to plan the last harvests for anything frost-sensitive still in the ground.

St. Catharines planting calendar

Approximate dates for common crops in St. Catharines, worked out from the local last frost around April 7. Warm crops go out after frost, cold-hardy crops a few weeks before it, and anything with an indoor start is counted back from its sow date.

Crop	Start indoors	Sow / transplant out	Approx. harvest
🍅 Tomato	March 3	April 21	July 10
🌶️ Pepper	February 17	April 21	July 5
🥒 Cucumber	—	April 14	June 11
🥬 Zucchini	—	April 14	June 3
🥬 Lettuce	—	March 17	May 1
🥬 Spinach	—	March 17	May 4
🫛 Peas	—	March 17	May 18
🥕 Carrots	—	March 17	May 24
🫘 Bush beans	—	April 7	May 27
🥬 Kale	February 17	March 17	May 11

Guideline dates from St. Catharines's average frost window, not a guarantee. GrowBlock tunes these to each variety you plant and adjusts as you build your beds.

This calendar is a starting point. In GrowBlock every date is tuned to the exact varieties you plant and updates as you lay out your beds, and you can share the plan with whoever you garden with, changes show up for both of you.

Build your St. Catharines garden plan

Frequently asked questions

When is the last frost in St. Catharines, ON?

Around April 7 on average, though it can vary by a week or two either way depending on the year.

What growing zone is St. Catharines?

St. Catharines is in zone 7a, with a frost-free season of about 218 days.

Gardening guides

Now that you have your dates, here is how to put them to work through the season:

More how-to on the GrowBlock gardening blog.

Frost dates for other cities

Barrie, ON Belleville, ON Brampton, ON Brantford, ON Cobourg, ON Guelph, ON

See frost dates for all Canadian cities covered by GrowBlock.