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.

The first opportunity to plant lithospermum in Knoxville can be determined by looking at the USDA zone info.

Planting Calendar for Lithospermum

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

You should not plant lithospermum until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant lithospermum in Knoxville 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 fully mature. 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 Knoxville the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Knoxville is just an average the actual date of last frost will vary from year to year. Half of the time in Knoxville you get surprised by a frost after April 15 so just be sure to be ready to cover your lithospermum in the event of one of those late frosts.

USDA Zone Info for Knoxville

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 Knoxville

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