Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of making a decision about when it's possible to plant cuphea is to consult the USDA zone info for Ontario.

Planting Calendar for Cuphea

Frost tolerance for cuphea:	Not tolerant of frost.
When to plant:	After the last frost.

It's a bad idea to plant cuphea until after the last frost when the weather gets warmer because they do not do well in cold weather.

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

Last Frost Date

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

Since the USDA zone info for Ontario is just an average the actual date of last frost will vary from year to year. Half of the time in Ontario it frosts late in the year after April 15 so make sure that you are prepared to protect your cuphea in the event of one of those late frosts.

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.