One of the best tools that you have as gardeners to help us determine 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.

A way of getting a good idea when you can plant skullcap is to consult the USDA zone info for Sheldon.

Planting Calendar for Skullcap

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

Skullcap require warm weather which means that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant skullcap in Sheldon is May. However, you really should wait until June 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. Any later than that and your skullcap may not have a chance to really do well. You can get started a couple of weeks earlier by starting your skullcap indoors.

Last Frost Date

On average the last frost is on May 15 in Sheldon. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Sheldon is just an average and the actual date of last frost is different every year. Half of the time in Sheldon you get a frost after May 15 so make sure that you are prepared to protect your skullcap in the event of a surprise late frost.

USDA Zone Info for Sheldon

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Sheldon

You may be interested in your other planting guides for Sheldon.