The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Decorah it's possible to determine when it's the best time to plant regal geranium.

Planting Calendar for Regal Geranium

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

Regal Geranium are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant regal geranium in Decorah 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 regal geranium and expect a good harvest is probably August. If you wait any later than that and your regal geranium may not have a chance to fully mature. If you are starting your regal geranium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Decorah 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.

Just be sure to remember that USDA zone info for Decorah is just an average and the actual date of last frost is different every year. Since half of the time in Decorah last frost occurs after May 15 be ready to protect your regal geranium if you have one of those late frosts.

USDA Zone Info for Decorah

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 Decorah

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