Before planting it is a good idea to find your USDA Zone info to estimate 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 earliest that you can plant pearl onions in Washington should be figured out by looking at the USDA zone info.

Planting Calendar for Pearl onions

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

You can plant pearl onions just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant pearl onions in Washington 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 pearl onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else your pearl onions may not have a chance to grow to maturity. Starting your pearl onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Washington the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for Washington is an average the actual date of last frost will vary from year to year. Half of the time in Washington you get a frost after March 15 so be sure to be ready to cover your pearl onions in the event of one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Washington

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