One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when it's possible to plant skullcap by using the USDA zone info for Vacaville.

Planting Calendar for Skullcap

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

It's probably a bad idea to plant skullcap until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant skullcap in Vacaville is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant skullcap and expect a good harvest is probably September. Any later than that and your skullcap may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your skullcap indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Vacaville. In the coldest months of winter you can expect an average low temperature of 25°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Vacaville and it is different every year. Half of the time in Vacaville you get a frost after February 15 so just be sure to be ready to protect your skullcap in the event of one of those late frosts.

USDA Zone Info for Vacaville

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Vacaville

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