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.

The USDA zone info for San Rafael can be read to determine when it's possible to plant scarlet pimpernels.

Planting Calendar for Scarlet Pimpernels

Frost tolerance for scarlet pimpernels:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Scarlet Pimpernels can survive in a tiny bit of cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant scarlet pimpernels in San Rafael 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 scarlet pimpernels and expect a good harvest is probably September. If you wait any later than that and your scarlet pimpernels may not have a chance to grow to maturity. If you are starting your scarlet pimpernels indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In San Rafael the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for San Rafael is just an average the actual date of last frost will vary from year to year. Half of the time in San Rafael last frost occurs after January 31 so just be sure to be ready to cover your scarlet pimpernels if you have one of those late frosts.

USDA Zone Info for San Rafael

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 Low	30°F
Highest Expected Low	35°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 San Rafael

You may be interested in your other planting guides for San Rafael.