Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of estimating when it's a good idea to plant fanflower is to use the USDA zone info for Helena.

Planting Calendar for Fanflower

Frost tolerance for fanflower:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since fanflower are not cold tolerant it is necessary to wait until after the last frost before you can plant them.

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

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.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Helena and it changes from year to year. Since half of the time in Helena last frost occurs after May 15 be ready to cover your fanflower 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.