The USDA Zone info is a great tool for gardeners to help us figure out 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.

The earliest that you can plant skullcap in Lake Bluff should be estimated by looking at the USDA zone info.

Planting Calendar for Skullcap

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

It's not a good idea to plant skullcap until after the last frost because they are not cold tolerant.

The earliest that you can plant skullcap in Lake Bluff 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. If you are starting your skullcap indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Lake Bluff. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Lake Bluff is not always accurate the actual date of last frost is different every year. Since half of the time in Lake Bluff there is a last frost after April 15 be ready to cover your skullcap if you have a surprise late frost.

USDA Zone Info for Lake Bluff

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 Lake Bluff

You may be interested in your other planting guides for Lake Bluff.