One of the best tools that you have as gardeners to help us figure out 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.

The first chance to plant aegopodium in Helena should be estimated by referring to the USDA zone info.

Planting Calendar for Aegopodium

Frost tolerance for aegopodium:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Aegopodium do ok in pretty solid cold which means that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant aegopodium in Helena 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 aegopodium and expect a good harvest is probably August. Any later than that and your aegopodium may not have a chance to really do well. If you are starting your aegopodium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Helena is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Helena you get a frost after May 15 so always be ready to protect your aegopodium if you have one of those late frosts.

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.