Regional Gardening Reports :: National Gardening Association

In the Garden:
Southwestern Deserts
September, 2008
Regional Report

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Lantana, Mexican hat coneflower, verbena, and a fruiting barrel cactus add color and provide sustenance for butterflies and birds.

Lantana's Potential Invasiveness

A reader's comment to a previous report questioned lantana's suitability for desert landscapes because of its reported invasiveness. I asked Ed Northam, invasive weed expert with the University of Arizona, for input and he had the following response on the subject. Since invasiveness of various nonnative species is such a severe threat to the Southwest's unique ecosystems, I thought it useful to include his comments below.

"My observation of this species (Lantana camera) in landscape plantings of the Salt and Gila River Valley bottoms [central Arizona] indicate that its survival is possible because of abundant imported water. If it did germinate in natural [not irrigated] Sonoran Desert environments, heat, drought and competition from cactus, creosote, palo verde, agave, desert broom, bursage, and mesquite vegetation will keep it from reproducing or encroaching into natural areas dominated by plants adapted to surviving in the Sonoran Desert.

"Successful colonization of escaped lantana in Maricopa County [central Arizona, Phoenix area] will be in moist areas such as Camp Creek, approximately 8 miles north of Carefree, Arizona [20 miles north of Phoenix]. Native vegetation in that perennial stream and riparian environment is predominately cottonwood, sycamore, hackberry, Arizona walnut, and willow, but I have personally observed a large population of Vinca major that was planted on the banks of Camp Creek many years ago. These kinds of moist situations are where I believe lantana plants could become serious pests in Arizona.

"Likewise, nonshade sites in higher elevation canyons with increased rainfall and milder summer conditions, such as Oak Creek Canyon [Sedona area] and Madera Canyon [southeast Arizona] would be ecologically threatened by lantana.

"There are a few herbarium specimens from nongarden, disturbed areas in Arizona listed on the ASU SEInet [Southwest Environmental Information Network] Web site [http://seinet/asu/edu] but nothing to indicate an eminent crisis for the state.

"So the bottom line is that I do not believe lantana is a threat to nonirrigated desert areas, but the parts of Arizona with perennial wetlands and riparian sites are possible places where lantana escapes could become problems."

After considering Northam's information, if you feel your landscape is sufficiently removed from wetlands and riparian sites, and make a decision to include lantana in your landscape for its other attributes (butterfly nectar, extended seasons of color, low maintenance, low water use), check out hybrid lantanas bred to produce fewer seeds. 'New Gold', which was trialed at Texas A&M University and included on the Texas Superstar Plant list, is an example.

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