Before planting it is a good idea to find your USDA Zone info to figure out 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 Decorah can be reffered to in order to determine when it's the best time to plant evolvulus.

Planting Calendar for Evolvulus

Frost tolerance for evolvulus:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant evolvulus until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant evolvulus in Decorah 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 evolvulus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your evolvulus may not have a chance to grow to maturity. If you are starting your evolvulus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Decorah may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Decorah you get a frost after May 15 so always be ready to protect your evolvulus 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.