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

By referring to the USDA zone info for Somersworth you should be able 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 the last frost has passed.

Since canna do not do well in cold weather you need to wait until after the last frost before you can plant them.

The earliest that you can plant canna in Somersworth 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 fully mature. If you are starting your canna indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Somersworth. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Somersworth is just an average the actual date of last frost is different every year. Since half of the time in Somersworth last frost occurs after April 15 be ready to cover your canna if you have one of those late frosts.

USDA Zone Info for Somersworth

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 Somersworth

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