The USDA Zone info is a great tool for gardeners to help us estimate 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 USDA zone info for Grass Valley should be looked at to figure out when it's possible to plant skullcap.

Planting Calendar for Skullcap

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

Since skullcap do not do well in cold weather it is necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant skullcap in Grass Valley 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. 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 February 15 in Grass Valley. In the coldest months of winter you should expect an average low temperature of 20°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Grass Valley and it changes from year to year. Since half of the time in Grass Valley there is a last frost after February 15 be ready to protect your skullcap if you have a late frost.

USDA Zone Info for Grass Valley

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

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

Plants to Grow in Grass Valley

You may be interested in your other planting guides for Grass Valley.