The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's the best time to plant lithospermum by reviewing the USDA zone info for Woburn.

Planting Calendar for Lithospermum

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

Lithospermum are not cold tolerant which tells us that it is necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant lithospermum in Woburn 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

The average date of last frost is April 15 in Woburn. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Woburn is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Woburn there is a last frost after April 15 be ready to protect your lithospermum in the event of a surprise late frost.

USDA Zone Info for Woburn

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 Woburn

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