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 iresene in San Bernardino can be figured out by referring to the USDA zone info.

Planting Calendar for Iresene

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

Iresene are not cold tolerant which tells us that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant iresene 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 iresene and expect a good harvest is probably September. Any later than that and your iresene may not have a chance to really do well. You can get started a few weeks earlier by starting your iresene indoors.

Last Frost Date

In San Bernardino the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for San Bernardino is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in San Bernardino there is a last frost after February 15 be ready to cover your iresene 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.