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.

A common way of making a decision about when to plant balloon flower is to check out the USDA zone info for Great Falls.

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 are barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant balloon flower in Great Falls 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

The average date of last frost is May 15 in Great Falls. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Great Falls is an average the actual date of last frost is different every year. Since half of the time in Great Falls last frost occurs after May 15 be ready to protect your balloon flower in the event of a late frost.

USDA Zone Info for Great Falls

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Great Falls

You may be interested in your other planting guides for Great Falls.