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.

By looking at the USDA zone info for Rapid City you should be able to figure out when you can plant browallia.

Planting Calendar for Browallia

Frost tolerance for browallia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Browallia are not cold tolerant which means that it is necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant browallia 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 browallia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your browallia may not have a chance to fully mature. If you are starting your browallia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Rapid City may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Rapid City it frosts late in the year after April 15 so always be ready to cover your browallia in the event of a surprise 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.