One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 Onalaska should be looked at to figure out when it's a good idea to plant balloon flower.

Planting Calendar for Balloon Flower

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

You can plant balloon flower just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant balloon flower 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 balloon flower and expect a good harvest is probably August. If you wait any later than that and your balloon flower may not have a chance to fully mature. You can get started a few weeks earlier by starting your balloon flower indoors.

Last Frost Date

In Onalaska the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember 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 will vary from year to year. Since half of the time in Onalaska you get surprised by a frost after May 15 be ready to cover your balloon flower in the event of a 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.