The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Waterville should be used to figure out when it's the best time to plant lithospermum.

Planting Calendar for Lithospermum

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

You can 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 Waterville 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 grow to maturity. You can get started a few weeks earlier by starting your lithospermum indoors.

Last Frost Date

In Waterville the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Waterville is just an average the actual date of last frost will vary from year to year. Half of the time in Waterville last frost occurs after April 15 so make sure that you are ready to protect your lithospermum in the event of one of those late frosts.

USDA Zone Info for Waterville

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 Waterville

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