The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of estimating when to plant four-o-clock flower is to use the USDA zone info for American Fork.

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.

Since four-o-clock flower require warm weather you have to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant four-o-clock flower in American Fork 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. If you wait any later than that and your four-o-clock flower may not have a chance to fully mature. If you are starting your four-o-clock flower indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In American Fork the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for American Fork is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in American Fork there is a last frost after April 15 so 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 American Fork

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in American Fork

You may be interested in your other planting guides for American Fork.