One of the first steps you take when you are making a decision about 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 figure out when it's the best time to plant asters by using the USDA zone info.

Planting Calendar for Asters

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

Asters do well in moderate cold which tells us that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant asters 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 asters and expect a good harvest is probably August. If you wait any later than that and your asters may not have a chance to fully mature. Starting your asters indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Green River is not always accurate the actual date of last frost changes from year to year. Since half of the time in Green River you get a frost after May 15 be ready to cover your asters 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.