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

By checking out the USDA zone info for San Bruno it's a good idea to determine when to 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 barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant datura in San Bruno 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. You probably don't want to wait any later than that or else your datura may not have a chance to fully mature. Starting your datura 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 Bruno. In the coldest months of winter you can expect an average low temperature of 30°F.

Keep in mind that USDA zone info for San Bruno is not always accurate and the actual date of last frost changes from year to year. Since half of the time in San Bruno it frosts late in the year after January 31 be ready to cover your datura if you have a surprise late frost.

USDA Zone Info for San Bruno

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Bruno

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