One of the first steps you take when you are figuring out your gardening schedule is find your 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.

The USDA zone info for Sonora should be read to estimate when you can plant skullcap.

Planting Calendar for Skullcap

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

You should not plant skullcap until after the last frost because they do not do well in cold weather.

The earliest that you can plant skullcap in Sonora 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. If you wait any later than that and your skullcap may not have a chance to really do well. Starting your skullcap indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Sonora the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Always keep in mind that USDA zone info for Sonora is an average and the actual date of last frost is different every year. Since half of the time in Sonora last frost occurs after February 15 be ready to cover your skullcap if you have a late frost.

USDA Zone Info for Sonora

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 Sonora

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