One of the best tools that you have as gardeners to help us determine 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 Somersworth can be looked at to figure out when it's the best time to plant sunflowers.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost.

Sunflowers do not do well in cold weather which means that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant sunflowers 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 sunflowers and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sunflowers may not have a chance to fully mature. If you are starting your sunflowers indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Somersworth. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Somersworth may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Somersworth you get a frost after April 15 be ready to cover your sunflowers in the event of a late frost.

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.