When to Plant Hypericum in Decorah, IA

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 earliest that you can plant hypericum in Decorah should be estimated by looking at the USDA zone info.


Planting Calendar for Hypericum

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

Hypericum are barely cold tolerant which tells us that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant hypericum
Possibly ok, but a risky time to plant hypericum
Probably not a good time to plant hypericum

The earliest that you can plant hypericum 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 hypericum and expect a good harvest is probably August. If you wait any later than that and your hypericum may not have a chance to grow to maturity. If you are starting your hypericum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Decorah. You should expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Decorah and it is different every year. Half of the time in Decorah you get surprised by a frost after May 15 so just be sure to be ready to cover your hypericum if you have a 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.