Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Dubuque you will be able to estimate when to plant purple coneflower.

Planting Calendar for Purple Coneflower

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

Purple Coneflower can survive in a tiny bit of cold which means that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant purple coneflower 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 purple coneflower and expect a good harvest is probably August. Any later than that and your purple coneflower may not have a chance to fully mature. You can get started a little bit earlier by starting your purple coneflower indoors.

Last Frost Date

In Dubuque the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Dubuque and it can change quite a bit from year to year. Since half of the time in Dubuque last frost occurs after April 15 be ready to cover your purple coneflower if you have a late frost.

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.