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.

It's a good idea to estimate when it's a good idea to plant lithospermum by referring to the USDA zone info for Somersworth.

Planting Calendar for Lithospermum

Frost tolerance for lithospermum:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since lithospermum do not do well in cold weather you have to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant lithospermum 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 lithospermum and expect a good harvest is probably August. Any later than that and your lithospermum may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your lithospermum indoors.

Last Frost Date

On average the last frost is on April 15 in Somersworth. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Somersworth is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Somersworth you get surprised by a frost after April 15 so make sure that you are ready to cover your lithospermum 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.