Try your hand at growing yarrow from seed.
Growing yarrow seeds is a fun and rewarding garden project. These pretty perennial bloomers flower the first year when grown from seed, so you’ll enjoy some color right away in your garden. Yarrow seeds provide an economical alternative when you need many yarrow plants to fill in a garden bed. All you need to get started is soil, a container and some patience.
Look for yarrow seeds from reputable seed sources. Yarrow cross pollinates easily, which means that seed may yield the same plant as the parent—or not, especially if any wild common yarrow (Achillea millefolium) grows nearby. If you want seeds to yield a specific, single color, focus on reputable seed companies as your primary source.
Many seeds come as a mix, that is, they yield yarrow flowers in a mix of colors. Examples include ‘Colorado Mix’, ‘Summer Berries’ mix and ‘Summer Pastels’ mix. With these seeds, you’ll grow yarrow plants that open blooms in a variety of colors. Over time, if you let plants set seed and self-sow in the garden, your proportion of colors may vary and shift with the genetically dominant hue becoming more prominent.
When sowing yarrow seed, you can start seeds before the growing season indoors or sow them directly into planting areas. For direct sowing outdoors, plant yarrow seeds in late fall in mild winter regions or in early spring (as soon as the soil can be worked) in cold winter zones. Tackle indoor starting about eight to ten weeks before you intend to tuck seedlings into the garden.
Yarrow seeds benefit from a cold period prior to planting. This process of providing cold is known as stratification. Ideally, yarrow seeds need a month-long stratification window. You can achieve this indoors by storing seeds in the refrigerator for a month. Place seeds in a damp paper towel tucked into a plastic zipper bag or in damp sand.
You can also achieve stratification by using winter sowing techniques to grow yarrow seeds. With this method, you plant yarrow seeds in containers outdoors in late fall. These containers should mimic mini-greenhouses, having a cover that can be sealed for winter but easily vented in spring. By using winter sowing methods, yarrow seeds naturally receive the cold treatment they need and sprout when spring air begins to warm soil.
Sow yarrow seed in a commercial seed starting mix that’s designed to get seedlings off to a solid start. Barely cover yarrow seeds. Aim for one-quarter inch of soil at most. Yarrow seeds need some light to germinate.
Germination is slow with yarrow seeds. If you keep soil temperature at 70°F, germination should occur within 14 to 28 days. At lower soil temperatures, it can take as a long as 100 days for yarrow seeds to sprout. You might consider investing in root zone heating mats if you’re planning on growing yarrow seeds.
Once you’re successfully growing yarrow in your garden, you can easily take divisions from established plants to start new plants. With this method, you can skip sowing and waiting for yarrow seeds to germinate.