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.

You should be able to figure out when to plant twinspur by looking at the USDA zone info for Rapid City.

Planting Calendar for Twinspur

Frost tolerance for twinspur:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant twinspur just a bit earlier in the year because they do well in moderate cold.

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

The last month that you can plant twinspur and expect a good harvest is probably September. If you wait any later than that and your twinspur may not have a chance to really do well. If you are starting your twinspur indoors then you might be able to get away with starting them a few weeks earlier.

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.

Always keep in mind that USDA zone info for Rapid City is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Rapid City you get surprised by a frost after April 15 so just be sure to be ready to cover your twinspur 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.