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

The best time to plant skullcap in Knoxville should be estimated by checking out the USDA zone info.

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 not a good idea to plant skullcap until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant skullcap in Knoxville 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. You can get started a couple of weeks earlier by starting your skullcap indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Knoxville. In the coldest months of winter you should expect an average low temperature of -15°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Knoxville and it can change quite a bit from year to year. Half of the time in Knoxville you get surprised by a frost after April 15 so always be ready to cover your skullcap if you have a late frost.

USDA Zone Info for Knoxville

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 Knoxville

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