One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Rapid City you can determine when you can plant purple coneflower by checking out the USDA zone info.

Planting Calendar for Purple Coneflower

Frost tolerance for purple coneflower:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Purple Coneflower do ok in moderate cold which tells us that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant purple coneflower in Rapid City is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant purple coneflower and expect a good harvest is probably August. Any later than that and your purple coneflower may not have a chance to fully mature. Starting your purple coneflower indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Rapid City. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Rapid City is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Rapid City there is a last frost after April 15 so make sure that you are prepared to protect your purple coneflower if you have a late frost.

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.