Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Ellensburg it's possible to estimate when it's possible to plant hardy asters.

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 do well in mild cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hardy asters in Ellensburg 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. You probably don't want to wait any later than that or else your hardy asters may not have a chance to fully mature. You can get started a little bit earlier by starting your hardy asters indoors.

Last Frost Date

On average the last frost is on April 15 in Ellensburg. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that USDA zone info for Ellensburg is an average and the actual date of last frost changes from year to year. Half of the time in Ellensburg there is a last frost after April 15 so be sure to be ready to protect your hardy asters in the event of one of those late frosts.

USDA Zone Info for Ellensburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Ellensburg

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