One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of determining when it's a good idea to plant datura is to consult the USDA zone info for National City.

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 do ok in mild cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant datura in National City 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 really do well. If you are starting your datura indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In National City the average date of last frost happens on January 31. You should expect an average low temperature of 35°F in the coldest months of winter.

Since the USDA zone info for National City is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in National City you get a frost after January 31 be ready to protect your datura in the event of one of those late frosts.

USDA Zone Info for National City

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in National City

You may be interested in your other planting guides for National City.