Rosemary is a woody, perennial herb, often used in cooking. The most common variety of rosemary is Rosemary officinalis. The best time to plant your rosemary plants is in the spring, after the risk of frost has passed. This allows the plant all summer to grow a thriving root system, which will help it survive over the winter. As rosemary grows best in well-draining soils, if you live in an area with clay soils, should lighten your soil by adding peat moss to improve drainage.
Look for rosemary plants with thin leaves and light colored flowers, such as light pink or white. These varieties are usually hardier.
Choose rosemary plants that grow upright, with long, straight stems. Rosemary varieties that grow by creeping along the ground tend to be less hardy.
Buy rosemary plants based on what you intend to use them for. If using for cooking, choose the upright variety. Ornamental-use rosemary is better suited to the lower-growing, bush variety.
Look for large rosemary plants with many branches and leaves. Avoid plants that look wilted or brown in color.
Rub the leaves of the plant and smell your hands. Different varieties of rosemary have slightly different scents. Choose the one you like the most.
Choose a variety suited to your climate. Varieties such as Albus, Herb Cottage and Salem rosemary tend to survive cold winters better than others.