Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Ontario should be reviewed to estimate when it's possible to plant string beans.

Planting Calendar for String beans

Frost tolerance for string beans:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

String beans require warm weather which means that it is necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant string beans 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 string beans and expect a good harvest is probably September. You probably don't want to wait any later than that or else your string beans may not have a chance to fully mature. If you are starting your string beans indoors then you might be able to get away with starting them a couple of 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 an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Ontario you get a frost after January 31 be ready to protect your string beans in the event of 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.