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 looking at the USDA zone info for Las Vegas it's a good idea to determine when it's the best time to plant four-o-clock flower.

Planting Calendar for Four-o-clock flower

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

Since four-o-clock flower require warm weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant four-o-clock flower 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 flower and expect a good harvest is probably September. Any later than that and your four-o-clock flower may not have a chance to fully mature. You can get started a few weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

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

Since the USDA zone info for Las Vegas is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Las Vegas you get surprised by a frost after February 15 so just be sure to be ready to cover your four-o-clock flower in the event of one of those late frosts.

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.