- Name: Evening Scented Stock - Other Common Names: Night Scented Stock - Scientific Name: Matthiola Bicornis Syn. Matthiola Longipetala Subsp. Bicornis - Color: Blue, White, Pink, & Purple - Plant Seeds: Outdoors After Frost / Indoors Weeks Before Last Frost - Bloom Time: All Summer - Hardiness Zone: N/A (But Reseeds Itself Easily, So It Acts Like A Perennial In All Zones) - Plant Height: 6 - 18" - Plant Spacing: 6 - 9" - Light Requirements: Sun - Part Shade - Soil & Water Preferences: Average - Quantity: 500 Seeds - Other: Stock Is Very Fragrant And Attracts Bees, Birds, & Butterflies.