One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 Zone 10a you can estimate when it's possible to plant four o' clock by reviewing the USDA zone info.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant four o' clock until after the last frost has passed because they require warm weather.

The earliest that you can plant four o' clock in Zone 10a 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 four o' clock and expect a good harvest is probably September. Any later than that and your four o' clock may not have a chance to grow to maturity. Starting your four o' clock indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Zone 10a. In the coldest months of winter you can expect an average low temperature of 30°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 10a and it will vary from year to year. Since half of the time in Zone 10a it frosts late in the year after January 31 be ready to cover your four o' clock if you have a surprise late frost.

USDA Zone Info for Zone 10a

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 Zone 10a

You may be interested in your other planting guides for Zone 10a.