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.

You should be able to figure out when it's a good idea to plant fanflower by looking at the USDA zone info for Rock Springs.

Planting Calendar for Fanflower

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

It's probably a bad idea to plant fanflower until after the last frost because they are not cold tolerant.

The earliest that you can plant fanflower in Rock Springs 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 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. If you are starting your fanflower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Rock Springs the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that USDA zone info for Rock Springs is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Rock Springs there is a last frost after April 15 so make sure that you are prepared to protect your fanflower if you have a late frost.

USDA Zone Info for Rock Springs

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Rock Springs

You may be interested in your other planting guides for Rock Springs.