One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for River Grove it's possible to estimate when it's the best time 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.

It's a bad idea to plant skullcap until after the last frost because they do not do well in cold weather.

The earliest that you can plant skullcap in River Grove 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 grow to maturity. Starting your skullcap indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for River Grove may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in River Grove you get surprised by a frost after April 15 be ready to cover your skullcap in the event of one of those late frosts.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.