One of the first steps you take when you are estimating your gardening schedule is find your 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.

In San Bruno you can estimate when it's possible to plant flax by using the USDA zone info.

Planting Calendar for Flax

Frost tolerance for flax:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Flax are moderately cold tolerant which tells us that you can start planting them earlier than other plants that might not handle the cold.

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

Last Frost Date

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

It's important to remember that USDA zone info for San Bruno is just an average and the actual date of last frost changes from year to year. Since half of the time in San Bruno you get surprised by a frost after January 31 be ready to cover your flax in the event of a surprise late frost.

USDA Zone Info for San Bruno

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 Bruno

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