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.

The earliest that you can plant rhubarb in Washington can be determined by using the USDA zone info.

Planting Calendar for Rhubarb

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

You can plant rhubarb just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant rhubarb in Washington is February. However, you really should wait until March if you don't want to take any chances.

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Washington. In the coldest months of winter you should expect an average low temperature of -10°F.

It's important to remember that USDA zone info for Washington may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Washington you get surprised by a frost after April 15 so make sure that you are prepared to protect your rhubarb in the event of one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Washington

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