Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Spencer should be reviewed 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 has passed.

Since lithospermum require warm weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant lithospermum in Spencer 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. If you wait 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 little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Spencer. In the coldest months of winter you should expect an average low temperature of -20°F.

Always keep in mind that USDA zone info for Spencer is an average and the actual date of last frost changes from year to year. Half of the time in Spencer it frosts late in the year after April 15 so make sure that you are ready to protect your lithospermum in the event of a surprise late frost.

USDA Zone Info for Spencer

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Spencer

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