One of the best tools that you have as gardeners to help us estimate 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.

By referring to the USDA zone info for San Francisco it's possible to estimate when it's possible to plant foxglove.

Planting Calendar for Foxglove

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

You can plant foxglove a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant foxglove in San Francisco 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 foxglove and expect a good harvest is probably October. If you wait any later than that and your foxglove may not have a chance to fully mature. Starting your foxglove indoors is a great way to get them started a little bit 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.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Francisco and it can change quite a bit from year to year. Half of the time in San Francisco it frosts late in the year after January 31 so make sure that you are prepared to protect your foxglove 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.