One of the first steps you take when you are figuring out 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.

You can estimate when to plant iberis in Great Falls by using the USDA zone info.

Planting Calendar for Iberis

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

You can plant iberis just a bit 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 iberis in Great Falls 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 iberis and expect a good harvest is probably August. If you wait any later than that and your iberis may not have a chance to really do well. You can get started a little bit earlier by starting your iberis indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Great Falls. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Great Falls is just an average the actual date of last frost changes from year to year. Half of the time in Great Falls it frosts late in the year after May 15 so always be ready to protect your iberis in the event of a surprise late frost.

USDA Zone Info for Great Falls

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 Great Falls

You may be interested in your other planting guides for Great Falls.