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.

In San Mateo you can determine when to plant datura by looking at the USDA zone info.

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 start planting them slightly earlier than more sensitive plants.

The earliest that you can plant datura in San Mateo 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. You can get started a few weeks earlier by starting your datura indoors.

Last Frost Date

On average the last frost has passed is on January 31 in San Mateo. It might get as low as 30°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for San Mateo and it will vary from year to year. Since half of the time in San Mateo you get a frost after January 31 be ready to cover your datura in the event of one of those late frosts.

USDA Zone Info for San Mateo

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 Mateo

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