One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when you can plant lithospermum by using the USDA zone info for Rantoul.

Planting Calendar for Lithospermum

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

Lithospermum do not do well in cold weather which means that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant lithospermum in Rantoul is April. However, you really should wait until May 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 really do well. 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 Rantoul the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Rantoul may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Rantoul you get a frost after April 15 be ready to protect your lithospermum in the event of a surprise late frost.

USDA Zone Info for Rantoul

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Rantoul

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