One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant sweet sultan in Decorah should be estimated by referring to the USDA zone info.

Planting Calendar for Sweet Sultan

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

Sweet Sultan do ok in moderate cold which means that you can plant them slightly earlier than plants that are more sensitive to the cold.

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

Last Frost Date

On average all chance of frost has passed is on May 15 in Decorah. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Decorah is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Decorah there is a last frost after May 15 be ready to protect your sweet sultan in the event of 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.