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

The USDA zone info for Waterloo can be read to figure out when it's the best time to plant canna.

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 because they require warm weather.

The earliest that you can plant canna in Waterloo 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 couple of weeks earlier.

Last Frost Date

In Waterloo the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Waterloo and it is different every year. Since half of the time in Waterloo you get a frost after April 15 be ready to protect your canna if you have one of those late frosts.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waterloo

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