One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A way of making a decision about when it's a good idea to plant scarlet pimpernels is to consult the USDA zone info for San Bernardino.

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.

You can plant scarlet pimpernels slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant scarlet pimpernels in San Bernardino 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. You probably don't want to wait any later than that or else your scarlet pimpernels may not have a chance to grow to maturity. Starting your scarlet pimpernels indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in San Bernardino. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for San Bernardino may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in San Bernardino you get a frost after February 15 be ready to cover your scarlet pimpernels if you have a late frost.

USDA Zone Info for San Bernardino

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 San Bernardino

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