One of the first steps you take when you are figuring out your gardening schedule is find your 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 it's a good idea to plant bok choi by looking at the USDA zone info.

Planting Calendar for Bok Choi

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

Bok Choi do well in some cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant bok choi 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 bok choi and expect a good harvest is probably August. Any later than that and your bok choi may not have a chance to grow to maturity. If you are starting your bok choi indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

It's important to remember 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 you get a frost after May 15 so be sure to be ready to protect your bok choi in the event of 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.