One of the best tools that you have as gardeners to help us figure out 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 using the USDA zone info for Ontario you will be able to determine when you can plant verbena.

Planting Calendar for Verbena

Frost tolerance for verbena:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since verbena are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant verbena in Ontario is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant verbena and expect a good harvest is probably August. If you wait any later than that and your verbena may not have a chance to grow to maturity. If you are starting your verbena indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Ontario. You should expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ontario and it will vary from year to year. Since half of the time in Ontario there is a last frost after April 15 be ready to cover your verbena in the event of a surprise 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.