The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Washington you should be able to determine when it's the best time to plant bittercress.

Planting Calendar for Bittercress

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

You can plant bittercress slightly earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

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

Last Frost Date

On average the last frost has passed is on April 15 in Washington. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for Washington may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Washington there is a last frost after April 15 be ready to protect your bittercress if you have a 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.