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.

It's a good idea to figure out when you can plant canna by reviewing the USDA zone info for Zone 4a.

Planting Calendar for Canna

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

It's probably a bad idea to plant canna until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant canna in Zone 4a is May. However, you really should wait until June 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 couple of weeks earlier by starting your canna indoors.

Last Frost Date

The average date of last frost is May 15 in Zone 4a. It might get as low as -30°F during the coldest months of winter.

Remember that USDA zone info for Zone 4a is an average and the actual date of last frost is different every year. Since half of the time in Zone 4a you get surprised by a frost after May 15 be ready to protect your canna in the event of a late frost.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in your other planting guides for Zone 4a.