Before planting it is a good idea to find your USDA Zone info to determine 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.

You can determine when it's possible to plant lithospermum in Berne by reviewing 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 require warm weather which means that you must wait until it warms up after the last frost has passed before you can plant them.

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

Last Frost Date

On average all chance of frost has passed is on April 15 in Berne. In the coldest months of winter you should expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Berne is just an average and the actual date of last frost will vary from year to year. Since half of the time in Berne there is a last frost after April 15 be ready to protect your lithospermum in the event of a late frost.

USDA Zone Info for Berne

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 Berne

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