The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Harrisburg should be reffered to in order to determine when it's possible to plant canna.

Planting Calendar for Canna

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

It's not a good idea to plant canna until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant canna in Harrisburg 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. You probably don't want to wait any later than that or else your canna may not have a chance to fully mature. If you are starting your canna indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Harrisburg. It might get as low as 0°F during the coldest months of winter.

Keep in mind that USDA zone info for Harrisburg is just an average and the actual date of last frost changes from year to year. Since half of the time in Harrisburg you get surprised by a frost after April 15 be ready to protect your canna if you have one of those late frosts.

USDA Zone Info for Harrisburg

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 Harrisburg

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