Invasive plant continues to spread in Paradise Valley

By Philip Haldiman
Mail | X: @PhilipHaldiman

An invasive plant has infested parts of Paradise Valley, particularly the northern part of the town.

Globe chamomile is an invasive African annual weed that crowds out native plants, and if it becomes too prevalent, can be a fire hazard in summer, according to the University of Arizona Cooperative Extension.

Officials with the Cooperative Extension say the species was identified in Arizona in the late 1990s, but had an outbreak around 2020, and is now spreading in Maricopa, Pinal and Pima counties, as well as across the Southwest in California, Nevada and Mexico.

Globe chamomile, its species name Oncosiphon pilulifer, is also known as Stinknet because of its strong, unpleasant, turpentine-like odor.

Paradise Valley Town Manager Andrew Ching said the invasion has been an ongoing problem in the town for a few years.

“We have put items in the Weekly (newsletter) about it previously, and we had a full Coffee with a Cop last year dedicated to the subject,” he said.

Globe chamomile is a member of the sunflower family and has finely dissected, carrot-like leaves, with spherical yellow flower heads made up of many small flowers.

The plant comes out during the winter, germinating from November to April and flowering from February to June, able to grow more than two feet tall.

“Dead Stinknet is a fire hazard in summer, when it becomes highly flammable brush topped by seed heads (dried flowers). These seed heads break up, helping the tiny seeds spread on wind or water and on animals, people and vehicles,” according to the Cooperative Extension.

In years of sufficient winter moisture, globe chamomile can go through up to three generations between November and the end of April, resulting in a prodigious production of plants and seeds in a short period of time, according to the Arizona Native Plant Society.

Globe chamomile readily infests sunny, disturbed soils that are not shaded by vegetation. It readily takes root in bare areas bordering any vegetation, both residential and wild land, the society states.

“The plant has very high reproductive potential with about 100 seeds in each head and hundreds of heads in each plant. Seeds can be viable in the soil for many years until favorable conditions to germinate,” said Ayman Mostafa, a spokesperson with the U of A Cooperative Extension.

Town of Paradise Valley officials urge residents to keep it from spreading into an invasive and suffocating blanket of vegetation that can damage the desert ecosystem.

Stinknet roots should be pulled from the ground by hand, by hula hoe or weed whacker. A variety of herbicides, including glyphosate and pre-emergent herbicides, are also effective.

But the U of A Extension warns to remove dead Stinknet carefully as it will shed thousands of seeds, which can live in soil up to five years.

Paul Staker, a volunteer with the McDowell Sonoran Conservancy in Scottsdale, is a veteran of a decade or more in the efforts to remove non-native plants from the desert. In a previous Independent Newsmedia article, he said there are many non-native plant species that have found their way into the desert, but the ones that are of most concern have probably been around for 100 to 150 years — a relatively recent introduction.

Generally, Staker said, invasive species arrived in the desert for practical purposes — feed for cattle, ornamental for landscaping, even hitching a ride into the state in decorative bouquets, as did globe chamomile, which has become a nuisance in Maricopa County and beyond in recent years.

Once they are introduced into an environment conducive to their growth, invasive plants will spread quickly, Staker said. They choke out or deprive native species of scarce water. They also dry out in the heat and become fuel for wildfires with those incidents increasing over recent years, he said.

Lead News Reporter Bob Burns contributed to this report.

Senior News Editor Philip Haldiman can be reached at phaldiman@iniusa.org, or on X @philiphaldiman. We’d like to invite our readers to submit their civil comments, pro or con, on this issue. Email AZOpinions@iniusa.org.

Philip Haldiman
Senior News Editor | Peoria

phaldiman@iniusa.org

Meet Philip
Haldiman is an award-winning journalist who most recently took first place for investigative reporting in 2023 from Arizona Newspapers Association. He joined Independent Newsmedia, Inc., USA, in 2015, covering Sun City West his first year. Since 2016, he has covered the city of Peoria. Prior to coming to INI, he was a reporter with The Arizona Republic for seven years, covering numerous cities throughout the Valley. Before that, he was a freelance writer.

Community: Haldiman spearheads the Peoria Independent Hometown Heroes Awards program, honoring local individuals and businesses that give back to the community. He has hosted local candidate forums over the years and is a member of the Society of Professional Journalists. Haldiman also served as a member of the Journalism Program Community Advisory Board at Glendale Community College. Outside journalism, Haldiman served as a member of the city of Peoria Complete Count Committee for the Census, 2019-2020. Lastly, he has served as a member of his HOA governing board since 2021.

Education: Arizona State University with a BA in Journalism and Mass Communications and a BA in Theater. 

Random Fact: Haldiman is a fourth-generation Arizonan as well as wrote and produced an autobiographical comic book about his time spent in Hollywood and his life as a cult film star.

Hobbies: He enjoys hiking Arizona’s mountainous landscapes and is currently working on a play for the stage.