The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to figure out when it's possible to plant alternaria by looking at the USDA zone info for San Bernardino.

Planting Calendar for Alternaria

Frost tolerance for alternaria:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since alternaria do not do well in cold weather you must wait until after the last frost before you can plant them.

The earliest that you can plant alternaria in San Bernardino 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 alternaria and expect a good harvest is probably September. Any later than that and your alternaria may not have a chance to fully mature. Starting your alternaria indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In San Bernardino the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

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 San Bernardino and it is different every year. Since half of the time in San Bernardino you get surprised by a frost after February 15 be ready to cover your alternaria in the event of one of those late frosts.

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.