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 Bristol you should be able to estimate when it's a good idea to plant lithospermum.

Planting Calendar for Lithospermum

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

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

The earliest that you can plant lithospermum in Bristol 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. You probably don't want to wait any later than that or else your lithospermum may not have a chance to fully mature. You can get started a few weeks earlier by starting your lithospermum indoors.

Last Frost Date

The average date of last frost is April 15 in Bristol. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Bristol is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Bristol there is a last frost after April 15 be ready to protect your lithospermum if you have a late frost.

USDA Zone Info for Bristol

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Bristol

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