One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant peonies in Helena should be determined by reviewing the USDA zone info.

Planting Calendar for Peonies

Frost tolerance for peonies:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant peonies a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant peonies in Helena is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant peonies and expect a good harvest is probably August. Any later than that and your peonies may not have a chance to fully mature. If you are starting your peonies indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Helena the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind 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 May 15 be ready to protect your peonies if you have a late frost.

USDA Zone Info for Helena

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Helena

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