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

The first opportunity to plant four-o-clock flower in Idaho Falls should be estimated by reviewing 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.

Four-o-clock flower are not cold tolerant which tells us that it is necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant four-o-clock flower in Idaho Falls 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. Any later than that and your four-o-clock flower may not have a chance to grow to maturity. If you are starting your four-o-clock flower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Idaho Falls the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Idaho Falls is just an average and the actual date of last frost changes from year to year. Since half of the time in Idaho Falls you get surprised by a frost after April 15 be ready to protect your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Idaho Falls

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°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 -15°F.

Plants to Grow in Idaho Falls

You may be interested in your other planting guides for Idaho Falls.