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 USDA zone info for Washington can be looked at to determine when it's a good idea to plant sweet peas.

Planting Calendar for Sweet Peas

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

Sweet Peas can survive in some cold which tells us that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant sweet peas 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 sweet peas and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet peas may not have a chance to fully mature. If you are starting your sweet peas indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Washington. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Washington and it is different every year. Half of the time in Washington it frosts late in the year after April 15 so just be sure to be ready to protect your sweet peas if you have a surprise late frost.

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.