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

In Decorah you can estimate when you can plant diascia by checking out the USDA zone info.

Planting Calendar for Diascia

Frost tolerance for diascia:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant diascia a little bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

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

Last Frost Date

In Decorah the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Decorah is just an average the actual date of last frost changes from year to year. Since half of the time in Decorah you get a frost after May 15 be ready to cover your diascia if you have a surprise late frost.

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.