Blue Arrow Cross Dahlia Flower Seeds Packaged with Instructions 50 Seeds Full sun, in rich moist well-drained medium. Bold flowers on strong stems make these a perfect border plant or even backyard cut flower with exceptional vase life. Grouped together they are ideal to add a riot of color to either the tropical or perennial garden border, or as a star performer in pots and planters on the patio or deck. They perform best in full sun in rich moisture retentive soil. Very Fragrant and excellent flower for borders, beds & arrangements.