One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of determining when it's the best time to plant yarrow is to use the USDA zone info for Troutdale.

Planting Calendar for Yarrow

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

Yarrow do well in cold which tells us that you can plant them much earlier than other frost tender plants.

The earliest that you can plant yarrow in Troutdale 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 really do well. If you are starting your yarrow indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Troutdale the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Troutdale is an average and the actual date of last frost is different every year. Since half of the time in Troutdale it frosts late in the year after March 15 be ready to protect your yarrow in the event of a late frost.

USDA Zone Info for Troutdale

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Troutdale

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