One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for San Anselmo should be reviewed to determine when you can plant datura.

Planting Calendar for Datura

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

Datura are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant datura in San Anselmo 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 datura and expect a good harvest is probably September. Any later than that and your datura may not have a chance to grow to maturity. If you are starting your datura indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on February 15 in San Anselmo. In the coldest months of winter you can expect an average low temperature of 25°F.

Just be sure to remember that USDA zone info for San Anselmo is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in San Anselmo you get surprised by a frost after February 15 be ready to cover your datura if you have a surprise late frost.

USDA Zone Info for San Anselmo

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Anselmo

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