One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant astilbe in Spokane can be estimated by checking out the USDA zone info.

Planting Calendar for Astilbe

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

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

The earliest that you can plant astilbe in Spokane 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 astilbe and expect a good harvest is probably August. You probably don't want to wait any later than that or else your astilbe may not have a chance to really do well. You can get started a couple of weeks earlier by starting your astilbe indoors.

Last Frost Date

In Spokane the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Keep in mind that USDA zone info for Spokane is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Spokane there is a last frost after April 15 be ready to protect your astilbe if you have a surprise late frost.

USDA Zone Info for Spokane

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 Spokane

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