One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant dianthus in Toronto should be estimated by reviewing the USDA zone info.

Planting Calendar for Dianthus

Frost tolerance for dianthus:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Dianthus are moderately cold tolerant which means that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant dianthus in Toronto 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 dianthus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your dianthus may not have a chance to really do well. Starting your dianthus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Toronto the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Toronto and it will vary from year to year. Half of the time in Toronto you get surprised by a frost after April 15 so make sure that you are ready to protect your dianthus in the event of a surprise late frost.

USDA Zone Info for Toronto

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 Toronto

You may be interested in your other planting guides for Toronto.