Yarrow is a perennial herb that grows throughout North America. Once established, it requires little care and spreads slowly. In some cases it can take over other plants and become invasive. Yarrow grows 1 to 3 feet tall and blooms from May to August in clusters of little white flowers. Planting yarrow is not difficult as long as you know how to care for the seed and create the right environment to foster growth.
Obtain the seeds of the yarrow plant. Purchase them or obtain them from an existing plant by pinching off dried flower heads. The seeds are contained within.
Stratify the seeds for a month before spring planting. Moisten--do not soak--a paper towel, and place the seeds inside. Place the paper towel in a Ziploc bag, and put it in the refrigerator. This cold period will mimic the winter cold the seeds need to germinate.
Choose a suitable area to plant the yarrow seeds with full sun and well-drained soil. The plant tolerates partial shade and poor soil conditions, but the soil must be well-drained.
Plant the seeds outdoors when the weather becomes warm enough. The seeds need soil temperatures between 60 or 65 degrees Fahrenheit to germinate. Do not plant them more than 1/4 inch into the soil as the seeds also need light to germinate.
Water the yarrow seeds, keeping them consistently moist until they start to grow on their own. The seeds take one to two weeks to germinate, and the plants take about two years to fully establish themselves. About 70 percent of the seeds grow successfully. Decrease watering after the yarrow starts to grow, allowing the soil to dry in between.