When to Plant Skullcap in Upland, CA

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

One way of figuring out when to plant skullcap is to consult the USDA zone info for Upland.


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 a bad idea to plant skullcap until after the last frost because they are not cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant skullcap
Possibly ok, but a risky time to plant skullcap
Probably not a good time to plant skullcap

The earliest that you can plant skullcap in Upland is February. However, you really should wait until March 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. Starting your skullcap indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Upland. In the coldest months of winter you should expect an average low temperature of 30°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Upland and it changes from year to year. Half of the time in Upland last frost occurs after January 31 so make sure that you are prepared to cover your skullcap in the event of a surprise late frost.

USDA Zone Info for Upland

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)January 31
Average Date of First Frost (fall)December 15
Lowest Expected Low30°F
Highest Expected Low35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Upland

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