Growing Rosemary - June 4, 2003
Jeff Schalau, County Director, Agent, Agriculture & Natural Resources
Arizona Cooperative Extension, Yavapai County
Rosemary (Rosmarinus officinalis) is an attractive, drought tolerant perennial plant that should be part of everyone's landscape or herb garden. Rosemary is a member of the mint family (Labiatae) and comes from the Mediterranean region where it often grows on cliffs near the ocean. It is hardy to 10 degrees F as long as it has some time to slowly harden off in the fall. It survives Prescott, Arizona winters and does very well when planted in the Verde Valley.
The most common varieties have blue flowers and are either the prostrate growth form (1 to 2 feet in height) or the upright growth form (3 to 6 feet in height). Rosemary is available in other flower colors: including white and pink. Many of these varieties were developed by European horticulturists and may be difficult to find in Arizona. In my research for this column, I found a comment from a Spanish nurseryman in Mallorca saying the "pinks" are weaker plants than the "whites".
The Mediterranean climate has mild winters with moderate precipitation and hot, dry summers. This is very similar to many parts of California. It's no accident that many California landscapers utilize several Mediterranean plant species. Whether we like it or not, many of our standard landscape plants were brought to Arizona from large nurseries in Southern California.
Rosemary can be grown from seed, but named cultivars grown by major nurseries are grown from cuttings. When purchasing them, I often look for 4-inch pots in the herb section of the nursery. They can be planted in any well-drained soil. The upright varieties make a good, informal evergreen hedge. If pruning is required, upright plants should be selectively pruned rather than sheared. Prostrate forms look best in cascading over masonry or rock walls or in rock gardens where the individual branches create interesting edge patterns. These can also be shaped easily by selective pruning.
Even though rosemary is "drought tolerant" it still needs some irrigation. I suggest giving plants frequent water (every 3 to 5 days) during the first growing season, and then decrease irrigation frequency once the root system has established and expanded. In my experience, rosemary plants that survive the first year will live for a long time. Once established, observe them and irrigate when they begin to show any signs of wilting. Excessively irrigated plants become very woody. Rosemary planted in native soil needs no fertilizer.
Rosemary should be dried before use and a little goes a long way. To do this, cut a few branches in the morning, then hang them to dry in a ventilated area out of direct sunlight. Once it is dried, simply rub the branches to separate the leaves from the stem and store leaves in a sealed glass jar. Use as a flavoring herb for roasted chicken, lamb, or beef, in soups and stews, and on oven-roasted potatoes.
The Romans and Greeks used rosemary and often associated it with love and the deities Eros and Aphrodite. Other references say that it is an effective insect repellent and that rosemary oil applied externally has cancer prevention properties. Note: the oil should not be taken internally. Even small doses can cause stomach, kidney and intestinal problems, and large amounts may be poisonous. Scientists at the University of Cincinnati say that the scent of rosemary is an effective memory stimulant. I should put a potted plant at my desk at work (if I can remember to water it).
The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at email@example.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://ag.arizona.edu/yavapai/anr/hort/byg/.
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Last Updated: May 29, 2003
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