One of the first steps you take when you are getting a good idea 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.

The USDA zone info for Dubuque should be reviewed to estimate when it's a good idea to plant sweet sultan.

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

The earliest that you can plant sweet sultan in Dubuque 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 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. You can get started a few weeks earlier by starting your sweet sultan indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Dubuque. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Dubuque may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Dubuque it frosts late in the year after April 15 so just be sure to be ready to protect your sweet sultan in the event of one of those late frosts.

USDA Zone Info for Dubuque

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Dubuque

You may be interested in your other planting guides for Dubuque.