Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when you can plant coreopsis by referring to the USDA zone info for Ontario.

Planting Calendar for Coreopsis

Frost tolerance for coreopsis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Coreopsis are moderately cold tolerant which tells us that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant coreopsis 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 coreopsis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your coreopsis may not have a chance to really do well. You can get started a few weeks earlier by starting your coreopsis indoors.

Last Frost Date

In Ontario the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Ontario may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Ontario you get a frost after April 15 be ready to cover your coreopsis if you have a late frost.

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.