One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 heliotrope by looking at the USDA zone info.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant heliotrope until after the last frost has passed because they do not do well in cold weather.

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

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

Last Frost Date

On average the last frost is on April 15 in Ontario. You should expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Ontario may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Ontario it frosts late in the year after April 15 so always be ready to protect your heliotrope in the event of one of those late frosts.

USDA Zone Info for Ontario

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Ontario

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