The USDA Zone info is a great tool for gardeners to help us estimate 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 way of getting a good idea when it's a good idea to plant balloon flower is to consult the USDA zone info for Green River.

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.

Since balloon flower are one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant balloon flower in Green River 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. You probably don't want to wait any later than that or else 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 Green River 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.

Keep in mind that USDA zone info for Green River may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Green River there is a last frost after May 15 so always be ready to protect your balloon flower in the event of one of those late frosts.

USDA Zone Info for Green River

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 Green River

You may be interested in your other planting guides for Green River.