The USDA Zone info is a great tool for gardeners to help us figure out 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.

In Boulder City you can estimate when you can plant skullcap by looking at 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.

Skullcap require warm weather which means that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant skullcap in Boulder City 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 fully mature. If you are starting your skullcap indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Boulder City the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Boulder City may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Boulder City there is a last frost after February 15 so always be ready to cover your skullcap in the event of one of those late frosts.

USDA Zone Info for Boulder City

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 Boulder City

You may be interested in your other planting guides for Boulder City.