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

The USDA zone info for Las Vegas 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.

It's not a good idea to plant four o' clock until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant four o' clock in Las Vegas 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. If you wait 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

The average date of last frost is February 15 in Las Vegas. You can expect an average low temperature of 20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Las Vegas is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Las Vegas you get a frost after February 15 be ready to cover your four o' clock in the event of a late frost.

USDA Zone Info for Las Vegas

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Las Vegas

You may be interested in your other planting guides for Las Vegas.