Yarrow is so easy to grow that it's a plant-it-and-forget-it herb that can thrive nearly anywhere. You won't want to forget it through, because it has many benefits. It's believed to be a healing herb for its many medicinal properties and is often used in organic beauty treatments. The colorful blooms make excellent cut flowers and can be dried and used in flower arrangements or in potpourri. Yarrow's colorful blooms brighten up any flower bed, and they are a perfect border plant.
Stratify the yarrow seeds about a month before the final frost of the season. Wet a paper towel and squeeze out the excess water. Wrap a few yarrow seeds in the paper towel, put them in a zip seal plastic bag, and close the bag.
Put the sealed bag in the refrigerator and leave it for a month. This process of stratification replicates a winter period that is often needed for seeds to germinate.
Plant the yarrow seeds outside in a sunny spot, covered by about ¼ inch of soil. Yarrow can thrive in poor soil as long as it has good drainage. The seeds should germinate quickly, usually about a week.
Thin the yarrow in two to four years if the plants become too crowded. Divide the clumps carefully with a sharp trowel. The clumps that you remove can be planted in another spot or given away.