Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Helena should be reffered to in order to determine when it's a good idea to plant copperleaf.

Planting Calendar for Copperleaf

Frost tolerance for copperleaf:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since copperleaf do not do well in cold weather you need to wait until after all chance of frost has passed before you can plant them.

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

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

Last Frost Date

On average the last frost has passed is on May 15 in Helena. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Helena is not always accurate the actual date of last frost changes from year to year. Since half of the time in Helena you get surprised by a frost after May 15 be ready to protect your copperleaf in the event of 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.