Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Mesa should be reviewed to figure out when you can plant four o' clock.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since four o' clock are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant four o' clock in Mesa is March. However, you really should wait until April 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 fully mature. If you are starting your four o' clock indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Mesa. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Mesa is just an average and the actual date of last frost changes from year to year. Half of the time in Mesa there is a last frost after February 15 so make sure that you are ready to protect your four o' clock if you have a surprise late frost.

USDA Zone Info for Mesa

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 Mesa

You may be interested in your other planting guides for Mesa.