One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when it's a good idea to plant aubrieta is to look at the USDA zone info for Bismarck.

Planting Calendar for Aubrieta

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

Aubrieta tend to make it in a little bit of cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant aubrieta in Bismarck 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 aubrieta and expect a good harvest is probably August. Any later than that and your aubrieta may not have a chance to really do well. Starting your aubrieta indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Bismarck the average date of last frost happens on May 15. You can expect an average low temperature of -30°F in the coldest months of winter.

Always keep in mind that USDA zone info for Bismarck is not always accurate and the actual date of last frost is different every year. Half of the time in Bismarck there is a last frost after May 15 so make sure that you are ready to cover your aubrieta if you have a late frost.

USDA Zone Info for Bismarck

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Bismarck

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