One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You will be able to estimate when it's possible to plant hardy asters by referring to the USDA zone info for Wyoming.

Planting Calendar for Hardy Asters

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

Hardy Asters tend to make it in some cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant hardy asters in Wyoming 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 hardy asters and expect a good harvest is probably August. If you wait any later than that and your hardy asters may not have a chance to grow to maturity. You can get started a little bit earlier by starting your hardy asters indoors.

Last Frost Date

The average date of last frost is April 15 in Wyoming. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Wyoming is an average the actual date of last frost is different every year. Half of the time in Wyoming you get surprised by a frost after April 15 so make sure that you are prepared to cover your hardy asters in the event of a late frost.

USDA Zone Info for Wyoming

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Wyoming

You may be interested in your other planting guides for Wyoming.