One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Decorah you can estimate when it's possible to plant radishes by checking out the USDA zone info.

Planting Calendar for Radishes

Frost tolerance for radishes:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Radishes do well in pretty solid cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant radishes 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 radishes and expect a good harvest is probably August. You probably don't want to wait any later than that or else your radishes may not have a chance to really do well. If you are starting your radishes 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. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just 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 last frost occurs after May 15 so make sure that you are prepared to protect your radishes 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.