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

In Onalaska you can estimate when it's a good idea to plant purple coneflower by checking out the USDA zone info.

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 tend to make it in mild cold which means that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant purple coneflower in Onalaska 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 purple coneflower and expect a good harvest is probably August. You probably don't want to wait any later than that or else your purple coneflower may not have a chance to really do well. You can get started a couple of weeks earlier by starting your purple coneflower indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Onalaska. In the coldest months of winter you can expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Onalaska and it can change quite a bit from year to year. Half of the time in Onalaska last frost occurs after May 15 so just be sure to be ready to cover your purple coneflower in the event of a surprise late frost.

USDA Zone Info for Onalaska

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 Onalaska

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