One of the first steps you take when you are getting a good idea 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 reviewing the USDA zone info for San Francisco you will be able to estimate when to plant canna.

Planting Calendar for Canna

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

Since canna are not cold tolerant it's important to wait until after the last frost before you can plant them.

The earliest that you can plant canna 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 canna and expect a good harvest is probably September. You probably don't want to wait any later than that or else your canna may not have a chance to grow to maturity. Starting your canna indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in San Francisco. You can expect an average low temperature of 35°F in 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 Francisco and it is different every year. Since half of the time in San Francisco it frosts late in the year after January 31 be ready to protect your canna in the event of one of those late frosts.

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.