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

By checking out the USDA zone info for Ishpeming you will be able 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 when the weather gets warmer.

Since lithospermum do not do well in cold weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant lithospermum in Ishpeming 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. You probably don't want to wait any later than that or else 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

The average date of last frost is May 15 in Ishpeming. In the coldest months of winter you should expect an average low temperature of -25°F.

Just be sure to remember that USDA zone info for Ishpeming is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Ishpeming you get a frost after May 15 be ready to protect your lithospermum if you have a late frost.

USDA Zone Info for Ishpeming

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 Ishpeming

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