One of the best tools that you have as gardeners to help us figure out 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.

In Barre you can determine when it's a good idea to plant lithospermum by looking at the USDA zone info.

Planting Calendar for Lithospermum

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

Lithospermum do not do well in cold weather which tells us that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant lithospermum in Barre is May. However, you really should wait until June 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. If you wait any later than that and your lithospermum may not have a chance to really do well. You can get started a few weeks earlier by starting your lithospermum indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Barre. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that USDA zone info for Barre is just an average and the actual date of last frost changes from year to year. Half of the time in Barre there is a last frost after May 15 so just be sure to be ready to protect your lithospermum in the event of one of those late frosts.

USDA Zone Info for Barre

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Barre

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