When to Plant Skullcap in Rialto, CA

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant skullcap in Rialto can be estimated by reviewing the USDA zone info.


Planting Calendar for Skullcap

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

You should not plant skullcap until after the last frost has passed because they require warm weather.

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 Rialto 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. Any later than that and your skullcap may not have a chance to really do well. If you are starting your skullcap indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Rialto may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Rialto it frosts late in the year after January 31 so make sure that you are prepared to cover your skullcap if you have a surprise late frost.

USDA Zone Info for Rialto

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 Rialto

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