One of the first steps you take when you are estimating your gardening schedule is find your 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.

By referring to the USDA zone info for Green River you will be able to determine when it's possible to plant datura.

Planting Calendar for Datura

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

Datura do ok in moderate cold which means that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

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

Last Frost Date

On average the last frost has passed is on May 15 in Green River. You can expect an average low temperature of -25°F in the coldest months of winter.

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 you get surprised by a frost after May 15 be ready to cover your datura in the event of 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.