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 first opportunity to plant blue throatwort in Washington can be estimated by referring to the USDA zone info.

Planting Calendar for Blue Throatwort

Frost tolerance for blue throatwort:	Not tolerant of frost.
When to plant:	After the last frost.

Since blue throatwort require warm weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant blue throatwort in Washington is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant blue throatwort and expect a good harvest is probably August. If you wait any later than that and your blue throatwort may not have a chance to really do well. Starting your blue throatwort indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Washington is just an average 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 just be sure to be ready to protect your blue throatwort in the event of 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.