One of the first steps you take when you are estimating 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.

The first chance to plant aubrieta in Helena can be determined by looking at the USDA zone info.

Planting Calendar for Aubrieta

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

You can plant aubrieta a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

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

Last Frost Date

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

Just be sure to remember that USDA zone info for Helena is just an average and the actual date of last frost changes from year to year. Since half of the time in Helena you get a frost after March 15 be ready to cover your aubrieta in the event of 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.