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 you should be able to determine when to plant blue lace flowers.

Planting Calendar for Blue Lace Flowers

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

You can plant blue lace flowers a bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant blue lace flowers 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 blue lace flowers and expect a good harvest is probably September. You probably don't want to wait any later than that or else your blue lace flowers may not have a chance to really do well. If you are starting your blue lace flowers indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on January 31 in San Francisco. You should expect an average low temperature of 35°F in the coldest months of winter.

Since the USDA zone info for San Francisco may not be accurate from year to year the actual date of last frost will vary 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 cover your blue lace flowers in the event of a surprise 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.