The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's possible to plant yarrow in Medical Lake by referring to the USDA zone info.

Planting Calendar for Yarrow

Frost tolerance for yarrow:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant yarrow quite a bit earlier in the year because they are very cold tolerant.

The earliest that you can plant yarrow in Medical Lake 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 yarrow and expect a good harvest is probably September. Any later than that and your yarrow may not have a chance to grow to maturity. If you are starting your yarrow indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Medical Lake. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Medical Lake is just an average the actual date of last frost changes from year to year. Half of the time in Medical Lake you get a frost after April 15 so be sure to be ready to protect your yarrow in the event of a surprise late frost.

USDA Zone Info for Medical Lake

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 Medical Lake

You may be interested in your other planting guides for Medical Lake.