The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant aurinia in Billings can be figured out by looking at the USDA zone info.

Planting Calendar for Aurinia

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

Aurinia are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them much earlier than more sensitive plants.

The earliest that you can plant aurinia in Billings 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 aurinia and expect a good harvest is probably August. Any later than that and your aurinia may not have a chance to really do well. If you are starting your aurinia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Billings. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that USDA zone info for Billings may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Billings there is a last frost after May 15 so make sure that you are prepared to protect your aurinia in the event of one of those late frosts.

USDA Zone Info for Billings

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Billings

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