One of the best tools that you have as gardeners to help us determine 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.

In Viroqua you can determine when it's the best time to plant canna by using the USDA zone info.

Planting Calendar for Canna

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

Since canna require warm weather it is important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant canna in Viroqua 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 fully mature. Starting your canna indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Viroqua. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Viroqua is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Viroqua there is a last frost after May 15 so make sure that you are prepared to protect your canna in the event of a surprise late frost.

USDA Zone Info for Viroqua

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Viroqua

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