When to Plant Rhubarb in Maple Valley, WA

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Maple Valley can be looked at to estimate when it's the best time to plant rhubarb.


Planting Calendar for Rhubarb

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

Since rhubarb are moderately cold tolerant you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

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

The earliest that you can plant rhubarb in Maple Valley 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 grow to maturity. You can get started a couple of weeks earlier by starting your rhubarb indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Maple Valley and it can change quite a bit from year to year. Half of the time in Maple Valley last frost occurs after March 15 so just be sure to be ready to cover your rhubarb if you have a surprise late frost.

USDA Zone Info for Maple Valley

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 Maple Valley

You may be interested in your other planting guides for Maple Valley.