One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's possible to plant skullcap by reviewing the USDA zone info for Stone Park.

Planting Calendar for Skullcap

Frost tolerance for skullcap:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

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

The earliest that you can plant skullcap in Stone Park 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. If you wait any later than that and your skullcap may not have a chance to grow to maturity. 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

The average date of last frost is April 15 in Stone Park. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Stone Park is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Stone Park you get a frost after April 15 be ready to cover your skullcap in the event of one of those late frosts.

USDA Zone Info for Stone Park

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 Stone Park

You may be interested in your other planting guides for Stone Park.