One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Green River you can estimate when it's the best time to plant trifolium by referring to the USDA zone info.

Planting Calendar for Trifolium

Frost tolerance for trifolium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since trifolium are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant trifolium 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 trifolium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your trifolium may not have a chance to fully mature. Starting your trifolium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Green River. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Green River and it is different every year. Since half of the time in Green River it frosts late in the year after May 15 be ready to cover your trifolium 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.