When is the best time to plant rosemary in Ohio?

Rosemary is propagated by seeds, cuttings and layers, and division of roots. (1) Seeds may be sown upon a warm, sunny border. (2) Cuttings, taken in August, 6 inches long, and dibbled into a shady border, two-thirds of their length in the ground, under a hand-glass, will root and be ready for transplanting into permanent quarters the following autumn. (3) Layering may be readily accomplished in summer by pegging some of the lower branches under a little sandy soil.