The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of figuring out when to plant balloon flower is to refer to the USDA zone info for Grinnell.

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.

Balloon Flower do well in a tiny bit of cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant balloon flower in Grinnell 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 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 really do well. If you are starting your balloon flower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Grinnell. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Grinnell is an average the actual date of last frost will vary from year to year. Since half of the time in Grinnell there is a last frost after April 15 be ready to protect your balloon flower in the event of one of those late frosts.

USDA Zone Info for Grinnell

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 Grinnell

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