The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Ontario it's possible to determine when it's a good idea to plant lisianthus.

Planting Calendar for Lisianthus

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

Lisianthus do not do well in cold weather which tells us that it is important to wait until it warms up after the last frost has passed before you can plant them.

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

Last Frost Date

In Ontario the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Ontario and it 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 lisianthus in the event of 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.