Before planting it is a good idea to find your USDA Zone info to determine 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 figure out when you can plant bidens by using the USDA zone info for Ontario.

Planting Calendar for Bidens

Frost tolerance for bidens:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since bidens do not do well in cold weather you really should wait until after the last frost before you can plant them.

The earliest that you can plant bidens 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 bidens and expect a good harvest is probably August. Any later than that and your bidens may not have a chance to really do well. Starting your bidens indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ontario. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Ontario is not always accurate 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 April 15 so make sure that you are ready to protect your bidens if you have a late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ontario

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