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.

One way of getting a good idea when it's the best time to plant canna is to refer to the USDA zone info for Missoula.

Planting Calendar for Canna

Frost tolerance for canna:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant canna until after the last frost has passed because they require warm weather.

The earliest that you can plant canna in Missoula 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. Any later than that and your canna may not have a chance to really do well. Starting your canna indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Missoula. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Missoula may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Missoula you get surprised by a frost after April 15 be ready to protect your canna in the event of one of those late frosts.

USDA Zone Info for Missoula

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 Missoula

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