One of the first steps you take when you are determining 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.

A common way of figuring out when it's a good idea to plant alternaria is to examine the USDA zone info for Ontario.

Planting Calendar for Alternaria

Frost tolerance for alternaria:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant alternaria until after the last frost when the weather gets warmer because they are not cold tolerant.

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

Last Frost Date

The average date of last frost is January 31 in Ontario. In the coldest months of winter you should expect an average low temperature of 30°F.

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. Since half of the time in Ontario you get surprised by a frost after January 31 be ready to cover your alternaria if you have a 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.