The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when to plant sweet williams in Decorah by using the USDA zone info.

Planting Calendar for Sweet Williams

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

Sweet Williams tend to make it in a little bit of cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant sweet williams 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 sweet williams and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet williams may not have a chance to fully mature. Starting your sweet williams indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Decorah. 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 not always accurate because it is based on the USDA zone info for Decorah and it is different every year. Half of the time in Decorah it frosts late in the year after May 15 so be sure to be ready to protect your sweet williams 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.