If you were driving Highway 60 through Gold Canyon two years ago this month, near Bashas’, you were probably impressed at roadside banks of bright yellow flowers. No, those weren’t gold poppies or marigolds. Instead they’re evidence of encroaching stinknet (Oncosiphon piluliferum), also commonly known as globe chamomile, though it isn’t a chamomile and shouldn’t be steeped in hot water.

A relative newcomer to the invasive weed scene in Arizona, this hardy plant native to South Africa has quickly spread since it was first confirmed here in 1997. Michael Chamberland’s paper on the subject reports: “By 2019 the plant had risen to public attention due to its conspicuous presence. Stinknet is now common in the Phoenix metro area and across much of Maricopa County.  It is spreading south along the I-10 corridor, becoming well established in Pinal County. Outbreaks have occurred within the Tucson metro area and also in rural parts of Pima County. Recent observations show stinknet has found its way into Mexico.”
Prevalent in the Phoenix area (1,000 feet elevation), thickets have been established at Anthem (2,000 feet) - and the outlook for Globe and possibly even Payson shows it could spread here, too. Recent reports around Sedona place the plant’s elevation tolerance up to 4,220 feet. As Chamberland’s paper concludes: “Stinknet’s potential upper elevation limit is not known.”

Chamberland is the guest speaker for this week’s gardening webinar, Thursday, May 6 at 11 a.m., hosted online and free through University of Arizona Cooperative Extension Gila County. The easiest, most convenient way to connect is via ‘click here’ direct hotlinks at extension.arizona.edu/gila, where you can also view dozens of prior Thursday webinar topics ranging from soil preparation to winter gardening, container gardening and more. University of Arizona Gila County Cooperative Extension Agent Chris Jones hosts this popular series, and Cooperative Extension’s website has an array of links to programs, talks and resources. Links are also conveniently posted each week on Facebook, where you can join Chris Jones and a network of Gila County gardeners at facebook.com/gilaextension. Want to be added to an email invite list for these gardening and horticulture workshops?  Call Chris Jones, Extension Agent, University of Arizona Gila County Cooperative Extension  at (928) 402-8586 or email ckjones@email.arizona.edu.

Presentations continue with:

• May 13 Waggin’ Vineyard and Estate

• May 20 Firewise Landscaping