One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for San Francisco can be reviewed to determine when it's a good idea to plant angel's trumpets.

Planting Calendar for Angel's Trumpets

Frost tolerance for angel's trumpets:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Angel's Trumpets do well in mild cold which means that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant angel's trumpets 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 angel's trumpets and expect a good harvest is probably September. If you wait any later than that and your angel's trumpets may not have a chance to grow to maturity. Starting your angel's trumpets indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for San Francisco is just an average and the actual date of last frost will vary from year to year. Half of the time in San Francisco last frost occurs after January 31 so make sure that you are prepared to protect your angel's trumpets in the event of 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.