One of the best tools that you have as gardeners to help us figure out 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 Rapid City should be looked at to determine when to 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.

Four O' Clock require warm weather which means that it's important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant four o' clock in Rapid City 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 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 may not have a chance to really do well. You can get started a little bit earlier by starting your four o' clock indoors.

Last Frost Date

The average date of last frost is April 15 in Rapid City. It might get as low as -20°F during the coldest months of winter.

It's important to remember that USDA zone info for Rapid City is an average and the actual date of last frost is different every year. Since half of the time in Rapid City last frost occurs after April 15 be ready to cover your four o' clock if you have one of those late frosts.

USDA Zone Info for Rapid City

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 Rapid City

You may be interested in your other planting guides for Rapid City.