One of the best tools that you have as gardeners to help us estimate 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.

You should be able to estimate when it's a good idea to plant achimenes by looking at the USDA zone info for Rapid City.

Planting Calendar for Achimenes

Frost tolerance for achimenes:	Not tolerant of frost.
When to plant:	After the last frost.

You can not plant achimenes until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant achimenes 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 achimenes and expect a good harvest is probably August. You probably don't want to wait any later than that or else your achimenes may not have a chance to really do well. You can get started a little bit earlier by starting your achimenes indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Rapid City. In the coldest months of winter you should expect an average low temperature of -20°F.

Remember that USDA zone info for Rapid City is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Rapid City last frost occurs after April 15 be ready to protect your achimenes in the event of 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.