- You Will Get 500 Seeds Of Purple Rockcress Rock Cress Aubrieta Deltoidea Flower Seeds. - Description: - Name: Purple Rockcress. - Scientific Name: Aubrieta Deltoidea. - Color: Purple. - Plant Seeds: Outdoors After Frost / Indoors Weeks Before Last Frost. - Plant Height: 4 - 6" - Plant Spacing: 18 - 24". - Bloom Time: Spring. - Hardiness Zone: 4 – 9. - Light Requirements: Sun - Part Shade. - Soil & Water Preferences: Average.