Which 'firewise' plants make the Top 10?
The end of the year usually sees a lot of "top 10" lists, from best new movies to best Lithuanian restaurants for under $5. So I thought I'd beat the rush and start off the year with my own list of favorite firewise plants.
Admittedly, this is a highly subjective list from the many hundreds of different kinds of firewise plants to choose from. In addition to their excellent fire-resistive qualities, these plants are also waterwise and well-adapted to our region.
#1. Cactus. For firewise you can't beat a cactus. A plant that stores water will not readily carry fire. There are more than 1,800 species in this large family. Many species are remarkably cold hardy and can tolerate even subzero temperatures. They also are very drought tolerant.
With a range of colorful flowers and unusual shapes and spines, they can add visual interest to a landscape or provide a hardy, low maintenance ground cover in hot, dry problem areas.
Besides cacti, there are many other succulent plants, including agaves, aloes, sedums, and yuccas. All are very firewise and can be planted even right up next to the house.
#2. Desert olive (Forestiera neomexicana). This small native tree or shrub, reaching about 12 feet in height, is deciduous, losing its leaves in fall or during stress. Because deciduous trees tend to hold more moisture, they can be excellent firewise choices. But not all deciduous trees are equally desirable.
A large, fast-growing deciduous tree is not a good firewise choice because of its high water demand and weaker wood prone to breakage. The desert olive, on the other hand, is drought tolerant and slow growing when not over-irrigated. Its light gray bark offers a nice contrast to the small, bright green leaves. It tends to grow as a shrub, but can be trained as a tree form by removing the lower branches. Bluish, fleshy fruits are produced in summer.
#3. Gambel oak (Quercus gambelii). Another native deciduous tree, gambel oak is also drought tolerant and slow growing. It can reach a height of up to 50 feet, though it may take centuries. The attractive gray trunk is deeply furrowed. It brings to the landscape not only fall color but acorns that are eaten by many different birds and mammals.
#4. Scrub Oak (Quercus turbinella). While on the subject of oaks, I have to include here my favorite little oak. The scrub oak often gets bad press, partly because of its scrubby form and sharp pointed leaves (which can present challenges when pruning). Because of its extreme drought tolerance (a 5-foot-high shrub can have roots extending down 20 or more feet into the ground) and its pleasant round shape of gray-green foliage, this hardy native deserves a place in any natural landscape. By removing dead branches and with only minimal pruning as needed, it can be maintained as an attractive, low growing firewise shrub or an informal hedge. The little acorns are especially favored by our local scrub jays.
#5. True mountain mahogany (Cercocarpus montanus). Reaching 10 feet in height, this native shrub is drought-tolerant and quite fire-resistive, despite its bad reputation with some firefighters. This is because of its tendency, like all chaparral shrubs, to accumulate a lot of dead wood that can flare up during a wildfire. Actually, mountain mahogany has been shown in laboratory tests to have a very low flammability. With regular pruning of any dead branches, it can be maintained as an attractive, open-branched shrub with low fuel load.
Like most horticulturists, I could go on for hours about my favorite plants. Since I have come to the end of the page, however, I will just list the remaining five. Please feel free to call me to discuss these and other possible firewise additions to your landscape:
#6. Desert willow (Chilopsis linearis). A small deciduous tree with pink to lavender flowers.
#7. Skunkbush (Rhus trilobata). Also known as three-leaf sumac in the nursery trade.
#8. New Mexico locust (Robinia neomexicana). Drought-tolerant small tree with pinkish flowers.
9. Blue grama (Bouteloua gracilis). An attractive, low-growing native bunchgrass.
#10. Nandina or heavenly bamboo (Nandina domestica). An attractive non-native shrub with colorful fall foliage and red berries - what's not to like?
Gene Twaronite is defensible space educator for Yavapai County Cooperative Extension. You can reach him at (928) 445-6590 ex. 231.