One of the best tools that you have as gardeners to help us estimate 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.

By referring to the USDA zone info for Ontario it's possible to figure out when to plant achimenes.

Planting Calendar for Achimenes

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

It's a bad idea to plant achimenes until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant achimenes 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 achimenes and expect a good harvest is probably August. If you wait any later than that and your achimenes may not have a chance to really do well. Starting your achimenes indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ontario. It might get as low as -15°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 can change quite a bit from year to year. Since half of the time in Ontario you get surprised by a frost after April 15 be ready to cover your achimenes in the event of a surprise 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.