One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

It's a good idea to figure out when to plant coleus by referring to the USDA zone info for Ontario.

Planting Calendar for Coleus

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

Since coleus are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant coleus 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 coleus and expect a good harvest is probably August. Any later than that and your coleus may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your coleus indoors.

Last Frost Date

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

Remember that the actual date of last frost is just an average 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 last frost occurs after April 15 be ready to cover your coleus if you have a late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ontario

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