The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Coal City it's a good idea to determine when it's a good idea to plant skullcap.

Planting Calendar for Skullcap

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

Skullcap require warm weather which tells us that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant skullcap in Coal City 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 fully mature. You can get started a few weeks earlier by starting your skullcap indoors.

Last Frost Date

On average the last frost is on April 15 in Coal City. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Coal City and it can change quite a bit from year to year. Since half of the time in Coal City there is a last frost after April 15 be ready to cover your skullcap in the event of one of those late frosts.

USDA Zone Info for Coal City

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 Coal City

You may be interested in your other planting guides for Coal City.