High Elevation Gardening Web Log "Blog"

Rocks do two things for a garden. They help hold moisture in the soil, and if they are dark rocks like our native malapais rocks, they’re like sponges, soaking up heat during the day and releasing it back into the soil and air at night. Rock gardens are especially useful for growing herbs because many herbs require a regular water supply and an air temperature a bit warmer than our customary Flagstaff chill.

Since most herbs like full sun, except for basil which likes afternoon shade, it is best to pick a sunny location for an herb rock garden. If the rock garden is on a rise, it is important to make sure the beds are level so that water soaks into the soil instead of running off. This can be accomplished by terracing the hill with rocks. In addition to rock terraces, rocks can be scattered throughout the garden. For a natural look several different sizes of rocks are best as well as being buried about one third of the way into the soil. It is really best to imitate nature as much as possible.

A curved walkway throughout the garden makes for ease in harvesting. If the most aromatic herbs are planted next to the walkways, their scent can more easily rub off on clothes and hands as well as filling the air with their perfume.

A favorite herb is sweet basil, a water thirsty and heat loving plant. Since it is very sensitive to the cold temperatures, it is best started indoors and planted outside only after all chance of frost has past. Another herb that will not survive a frost is rosemary. Rosemary is a very slow growing plant so it is best to dig it up each fall, bring it inside to a sunny window. It will do just fine until the following summer when it can once again be put it outside.

Many herbs are perennials here and will come back year after year. Sage, mint, chives, sweet marjoram, oregano, and thyme do quite well in Flagstaff.

A wonderful addition to any rock garden is one of the many lavenders that are perfectly suited for Flagstaff. A favorite is Lavendula augustifolia which has beautiful and fragrant purple blossoms. There is even a white lavender (Lavendula alba) which brightens up a garden, interspersed among the more traditional purple lavenders. These shrubs are also drought tolerant and can be planted in the drier outlying areas of an herb garden.

Most of these herbs produce beautiful flowers so an herb rock garden won’t be merely a sea of green. Many herbs are easily started from seed which is inexpensive. Some are more easily purchased at a nursery. Whatever you do, a rock garden of herbs is one of those few things in life that is tasty, healthy, beautiful and fun.

Cindy Wilder is a Master Gardener volunteer. Dana Prom Smith is a Master Gardener volunteer and the coordinating editor for the Master Gardener Column. He can be contacted at stpauls@npgcable.com. For more information about the Master Gardener Program, call Hattie Braun at 774-1868 ext.17 or visit our Web Site: highelevationgardening.arizona.edu.