Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant canna in Ottawa by reviewing the USDA zone info.

Planting Calendar for Canna

Frost tolerance for canna:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since canna are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

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

Last Frost Date

The average date of last frost is April 15 in Ottawa. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Ottawa is an average the actual date of last frost is different every year. Half of the time in Ottawa last frost occurs after April 15 so just be sure to be ready to protect your canna if you have a surprise late frost.

USDA Zone Info for Ottawa

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 Ottawa

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