Before planting it is a good idea to find your USDA Zone info to figure out 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.

You should be able to figure out when to plant canna by using the USDA zone info for Washington.

Planting Calendar for Canna

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

You really shouldn't plant canna until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant canna in Washington 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 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 Washington. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Washington is just an average the actual date of last frost changes from year to year. Since half of the time in Washington last frost occurs after April 15 be ready to cover your canna in the event of a late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Washington

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