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.

You can figure out when you can plant four-o-clock flower in Wyoming by referring to the USDA zone info.

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 has passed.

Since four-o-clock flower are not cold tolerant you really should wait until after the last frost before you can plant them.

The earliest that you can plant four-o-clock flower in Wyoming is April. However, you really should wait until May 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 August. You probably don't want to wait any later than that or else your four-o-clock flower may not have a chance to really do well. You can get started a little bit earlier by starting your four-o-clock flower indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Wyoming. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Wyoming is not always accurate the actual date of last frost will vary from year to year. Half of the time in Wyoming last frost occurs after April 15 so always be ready to cover your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Wyoming

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Wyoming

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