One of the first steps you take when you are estimating your gardening schedule is find your 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 can be read to determine when it's the best time to plant borage.

Planting Calendar for Borage

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

Borage are moderately cold tolerant which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant borage 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 borage and expect a good harvest is probably September. If you wait any later than that and your borage may not have a chance to fully mature. You can get started a few weeks earlier by starting your borage indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Rapid City and it can change quite a bit from year to year. Since half of the time in Rapid City you get a frost after April 15 be ready to cover your borage 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.