Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In River Grove you can estimate when to plant lithospermum by using the USDA zone info.

Planting Calendar for Lithospermum

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

You really shouldn't plant lithospermum until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant lithospermum in River Grove 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. 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

On average the last frost when the weather gets warmer is on April 15 in River Grove. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for River Grove is just an average the actual date of last frost will vary from year to year. Half of the time in River Grove it frosts late in the year after April 15 so always be ready to cover your lithospermum in the event of a surprise late frost.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.