Outsidepride Dahlia Dandy Plant Flower Seed Mix - 1000 Seeds This dahlia mix will brighten up any flower garden in USDA Zones 3 - 10. Dahlia Dandy mix is an annual flower mix with eye popping colors. These flower seeds will grow to approximately 24 inches in height. There are many shades of red, yellow, orange and white all with matching or contrasting inner collars of quilled petals. Sow 2 - 3 Seeds per flowering plant you want in your garden.