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.

The USDA zone info for Green River can be read to estimate when to plant campanula.

Planting Calendar for Campanula

Frost tolerance for campanula:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Campanula do well in moderate cold which tells us that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant campanula in Green River 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 campanula and expect a good harvest is probably August. You probably don't want to wait any later than that or else your campanula may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your campanula indoors.

Last Frost Date

The average date of last frost is May 15 in Green River. In the coldest months of winter you can expect an average low temperature of -25°F.

Remember that USDA zone info for Green River is not always accurate and the actual date of last frost changes from year to year. Half of the time in Green River you get surprised by a frost after May 15 so always be ready to cover your campanula if you have a late frost.

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.