When to Plant Ornamental Grasses in Issaquah, WA

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

A way of making a decision about when it's possible to plant ornamental grasses is to consult the USDA zone info for Issaquah.


Planting Calendar for Ornamental Grasses

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

Ornamental Grasses do ok in moderate cold which tells us that you can start planting them slightly earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant ornamental grasses
Possibly ok, but a risky time to plant ornamental grasses
Probably not a good time to plant ornamental grasses

The earliest that you can plant ornamental grasses in Issaquah 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 ornamental grasses and expect a good harvest is probably August. Any later than that and your ornamental grasses may not have a chance to really do well. Starting your ornamental grasses indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Issaquah the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

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

USDA Zone Info for Issaquah

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°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 20°F.

Plants to Grow in Issaquah

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