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

A common way of making a decision about when you can plant lithospermum is to refer to the USDA zone info for Minnetonka.

Planting Calendar for Lithospermum

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

It's a bad idea to plant lithospermum until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant lithospermum in Minnetonka 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 grow to maturity. Starting your lithospermum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Minnetonka is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Minnetonka it frosts late in the year after May 15 be ready to protect your lithospermum if you have a late frost.

USDA Zone Info for Minnetonka

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 Minnetonka

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