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.

The best time to plant lithospermum in Rhinelander should be figured out by checking out the USDA zone info.

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 before you can plant them.

The earliest that you can plant lithospermum in Rhinelander 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. 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 May 15 in Rhinelander. It might get as low as -30°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Rhinelander and it changes from year to year. Since half of the time in Rhinelander last frost occurs after May 15 be ready to cover your lithospermum in the event of a surprise late frost.

USDA Zone Info for Rhinelander

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 Rhinelander

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