One of the best tools that you have as gardeners to help us figure out 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 checking out the USDA zone info for San Jose you should be able to determine when it's the best time 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 tend to make it in mild cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant datura in San Jose 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 really do well. You can get started a couple of weeks earlier by starting your datura indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in San Jose. You should expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that USDA zone info for San Jose is just an average and the actual date of last frost is different every year. Since half of the time in San Jose last frost occurs after February 15 be ready to cover your datura if you have a surprise late frost.

USDA Zone Info for San Jose

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 Jose

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