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

You will be able to estimate when to plant datura by using the USDA zone info for South Pasadena.

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 plants that are more sensitive to the cold.

The earliest that you can plant datura in South Pasadena 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. If you wait 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 little bit earlier.

Last Frost Date

In South Pasadena the average date of last frost happens on January 31. You can expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for South Pasadena is an average the actual date of last frost will vary from year to year. Since half of the time in South Pasadena you get surprised by a frost after January 31 be ready to cover your datura in the event of one of those late frosts.

USDA Zone Info for South Pasadena

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 South Pasadena

You may be interested in your other planting guides for South Pasadena.