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 you can plant iberis in Helena by reviewing 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.

Iberis are moderately cold tolerant which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant iberis 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 iberis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your iberis may not have a chance to fully mature. Starting your iberis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Helena. It might get as low as 10°F during the coldest months of winter.

Always keep in mind that USDA zone info for Helena is an average and the actual date of last frost changes from year to year. Half of the time in Helena last frost occurs after March 15 so be sure to be ready to cover your iberis in the event of a surprise 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.