- You Will Get 600 Seeds Of Red Yarrow Achillea Millefolium Rubra Flower Seeds. - Description: - Name: Red Yarrow. - Scientific Name: Achillea Millefolium Rubra. - Color: Red With Yellow Centers. - Plant Seeds: Outdoors After Frost / Indoors Weeks Before Last Frost. - Plant Height: 12- 24". - Plant Spacing: 12 - 15". - Bloom Time: May – Nov. - Hardiness Zone: 3 - 10 (& Reseeds Itself Easily). - Light Requirements: Sun - Part Shade. - Soil & Water Preferences: Average – Dry.