Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Green River you can determine when it's possible to plant twinspur by looking at the USDA zone info.

Planting Calendar for Twinspur

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

Twinspur can survive in moderate cold which means that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant twinspur 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 twinspur and expect a good harvest is probably August. If you wait any later than that and your twinspur may not have a chance to really do well. Starting your twinspur indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Green River the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Green River is an average the actual date of last frost will vary from year to year. Since half of the time in Green River last frost occurs after May 15 be ready to cover your twinspur if you have a surprise 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.