The USDA Zone info is a great tool for gardeners to help us estimate 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.

By checking out the USDA zone info for Pierre it's a good idea to determine when it's a good idea to plant lithospermum.

Planting Calendar for Lithospermum

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

Since lithospermum require warm weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant lithospermum in Pierre 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 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 Pierre the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Pierre may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Pierre last frost occurs after May 15 so make sure that you are prepared to protect your lithospermum in the event of one of those late frosts.

USDA Zone Info for Pierre

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 Pierre

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