Rosemary herbs (Rosmarinus officinalis) are actually evergreen, perennial flowering shrubs that are native to Asia and the Mediterranean region. Rosemary has pine-like needles that are used to flavor a wide range of cuisines. Because rosemary shrubs are cold-hardy, you can plant them in the ground outdoors in most climates. Rosemary grows 3 to 6 feet in height and up to 3 feet in width, thriving in even drought conditions. One of the easiest herbs to grow, a rosemary shrub can live for more than 20 years.
Plant your rosemary shrubs in mid- to late spring, after all chance of frost has passed. Select a planting spot for your rosemary herbs that has lightweight, slightly sandy soil and that's in full to partial sunlight but has some shelter from winter winds.
Dig a planting hole for your rosemary herbs that's 1 ½ times the depth and width of the nursery container. Add ½ to 1 inch of sharp sand to the bottom of the planting hole.
Mix into the displaced soil some sharp sand, so that you have equal parts native soil and sand. Remove the rosemary shrub from the nursery container and set the roots into the planting hole.
Backfill the planting hole with the soil and sand mixture, planting the rosemary at about the same depth as it was in the nursery container. If you're planting more than one rosemary shrub, space them at least 3 feet apart.
Water the rosemary to soak the soil around the roots. Throughout the year, water your rosemary herbs only when the soil is dried out.
Feed your rosemary plants once each month from April until October with an all-purpose liquid plant fertilizer. Follow the dosage instructions on the fertilizer label.
Harvest the rosemary needle leaves throughout the summer. In autumn, pick the leaves in the morning for best oil-content and quality. You can use the fresh leaves in dishes immediately after picking them, or you can dry or freeze the leaves.