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

In Three Rivers you can determine when it's possible to plant skullcap by using the USDA zone info.

Planting Calendar for Skullcap

Frost tolerance for skullcap:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since skullcap are not cold tolerant it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant skullcap in Three Rivers 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 skullcap and expect a good harvest is probably August. You probably don't want to wait any later than that or else your skullcap may not have a chance to really do well. If you are starting your skullcap indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Three Rivers the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Three Rivers is not always accurate the actual date of last frost is different every year. Half of the time in Three Rivers it frosts late in the year after April 15 so be sure to be ready to cover your skullcap in the event of one of those late frosts.

USDA Zone Info for Three Rivers

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 Three Rivers

You may be interested in your other planting guides for Three Rivers.