One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 Chelsea can be reffered to in order to estimate when it's possible to plant lithospermum.

Planting Calendar for Lithospermum

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

You should not plant lithospermum until after the last frost because they require warm weather.

The earliest that you can plant lithospermum in Chelsea 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. If you are starting your lithospermum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Chelsea the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Chelsea is an average the actual date of last frost changes from year to year. Since half of the time in Chelsea it frosts late in the year after April 15 be ready to protect your lithospermum if you have one of those late frosts.

USDA Zone Info for Chelsea

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Chelsea

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