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Last Frost Date for Oakville, ON

Ontario · Growing Zone 6b

Last Spring Frost
April 10
First Fall Frost
November 6
Growing Season
210 days
Hardiness Zone
6b

Gardeners in Oakville, ON can expect the average last spring frost around April 10, and the first fall frost around November 6, based on historical Environment Canada frost data for the area. That gives Oakville a frost-free growing season of roughly 210 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 Oakville 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 Oakville's first fall frost approaches in November, it's time to plan the last harvests for anything frost-sensitive still in the ground.

Oakville planting calendar

Approximate dates for common crops in Oakville, worked out from the local last frost around April 10. 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.

CropStart indoorsSow / transplant outApprox. harvest
🍅 Tomato March 6 April 24 July 13
🌶️ Pepper February 20 April 24 July 8
🥒 Cucumber — April 17 June 14
🥬 Zucchini — April 17 June 6
🥬 Lettuce — March 20 May 4
🥬 Spinach — March 20 May 7
🫛 Peas — March 20 May 21
🥕 Carrots — March 20 May 27
🫘 Bush beans — April 10 May 30
🥬 Kale February 20 March 20 May 14

Guideline dates from Oakville'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 Oakville garden plan

Frequently asked questions

When is the last frost in Oakville, ON?

Around April 10 on average, though it can vary by a week or two either way depending on the year.

What growing zone is Oakville?

Oakville is in zone 6b, with a frost-free season of about 210 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

See frost dates for all Canadian cities covered by GrowBlock.