One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for San Francisco it's a good idea to figure out when to plant bunching onions.

Planting Calendar for Bunching Onions

Frost tolerance for bunching onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bunching Onions are one of those plants that can tolerate a tiny bit of cold weather which means that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant bunching onions in San Francisco 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 bunching onions and expect a good harvest is probably September. If you wait any later than that and your bunching onions may not have a chance to really do well. Starting your bunching onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in San Francisco. In the coldest months of winter you can expect an average low temperature of 35°F.

Since the USDA zone info for San Francisco may not be accurate from year to year the actual date of last frost is different every year. Half of the time in San Francisco last frost occurs after January 31 so make sure that you are ready to protect your bunching onions if you have a late frost.

USDA Zone Info for San Francisco

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Francisco

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