The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 Spearfish can be looked at to determine when you can plant aurinia.

Planting Calendar for Aurinia

Frost tolerance for aurinia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since aurinia do well in cold you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant aurinia in Spearfish 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 aurinia and expect a good harvest is probably September. Any later than that and your aurinia may not have a chance to grow to maturity. Starting your aurinia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Spearfish the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Just be sure to remember that USDA zone info for Spearfish is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Spearfish you get a frost after April 15 so make sure that you are prepared to protect your aurinia in the event of a late frost.

USDA Zone Info for Spearfish

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 Spearfish

You may be interested in your other planting guides for Spearfish.