One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Ontario you can determine when to plant nasturtium by using the USDA zone info.

Planting Calendar for Nasturtium

Frost tolerance for nasturtium:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You should not plant nasturtium until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant nasturtium in Ontario is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant nasturtium and expect a good harvest is probably September. If you wait any later than that and your nasturtium may not have a chance to really do well. If you are starting your nasturtium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in Ontario. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for Ontario is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Ontario you get a frost after January 31 so always be ready to protect your nasturtium in the event of a surprise late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Ontario

You may be interested in your other planting guides for Ontario.