Before planting it is a good idea to find your USDA Zone info to figure out your garden 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 Helena should be looked at to figure out when to plant aurinia.

Planting Calendar for Aurinia

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

Aurinia do ok in pretty solid cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant aurinia in Helena 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. If you wait 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 few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Helena. You can expect an average low temperature of 10°F in the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Helena and it changes from year to year. Since half of the time in Helena you get a frost after March 15 be ready to protect your aurinia if you have a late frost.

USDA Zone Info for Helena

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Helena

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