Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when it's possible to plant lithospermum by reviewing the USDA zone info for North Branch.

Planting Calendar for Lithospermum

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

You really shouldn't plant lithospermum until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant lithospermum in North Branch 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. Starting your lithospermum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in North Branch. In the coldest months of winter you should expect an average low temperature of -30°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for North Branch and it is different every year. Half of the time in North Branch you get surprised by a frost after May 15 so make sure that you are prepared to cover your lithospermum if you have one of those late frosts.

USDA Zone Info for North Branch

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in North Branch

You may be interested in your other planting guides for North Branch.