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.

You will be able to estimate when it's the best time to plant leeks by using the USDA zone info for San Bernardino.

Planting Calendar for Leeks

Frost tolerance for leeks:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Leeks do well in cold which tells us that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant leeks in San Bernardino is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant leeks and expect a good harvest is probably October. You probably don't want to wait any later than that or else your leeks may not have a chance to really do well. If you are starting your leeks indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is 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 is not always accurate the actual date of last frost will vary from year to year. Half of the time in San Bernardino you get a frost after February 15 so be sure to be ready to cover your leeks if you have a surprise 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.