Achillea filipendulina. The classic golden-flowered Yarrow is an old-world herb that grows to a height of 120cm (47") making it a focal plant in the middle or back of flower beds. Yarrow Achillea seeds yield brilliant yellow 15 cm (6") flowers that bloom from late June to September. This is a highly drought-resistant plant, so excellent for xeriscaping. Use it as a companion plant in the vegetable garden, too - its scent repels aphids, but attracts hoverflies, ladybugs and wasps that feed on common garden pests. Enzymes in the cells of this herb help to break compost down swiftly. Simply cut stalks down at the end of the season and breaking them into manageable pieces to be added whenever you top up the compost heap.
The scent of yarrow repels aphids, but their flowers attract hoverflies, lady beetles, and parasitoid wasps that prey on aphids and garden grubs. The leaves and stems of yarrow contain enzymes that break down rapidly, so it can be added to the compost raw or as a tea to accelerate the heap. Achillea is a hardy perennial also known as milfoil. Continue reading below for tips on how to grow yarrow from seed.
Season & Zone
Exposure: Full sun
Zone: A. filipendulina is hardy to Zone 3. A. millefolium is hardy to Zone 4.
Sow indoors 8-10 weeks before planting out after the last frost date. Transplant or direct sow in early spring or early autumn. Optimal soil temperature for germination: 15-18°C (60-65°F). Seeds can take 10 to as long as 100 days to sprout, so be patient. Bottom heat speeds germination.
Sow on the surface of the soil, under bright lights if starting indoors. Transplants can go out while the soil is still cool and there is still some risk of light frost. Space transplants at 30-60cm (12-24″) apart.
Yarrow is a tough plant that is suitable for xeriscaping, and it will adapt to pretty much any soil. For best results, grow in a loamy, well drained soil with a pH of 5.5 to 7.0. Divide plants every 3-4 years. Cut plants to ground level in autumn.