As a part of the Prescott Creeks mission to achieve healthy watersheds and clean waters, we invest substantial effort into managing non-native, invasive plant species. Some people call them weeds. But what is a “weed?” Are those yellow flowers that pop up in your garden a weed? Are the pink, prickly things along the trail a
Siberian elm (Ulmus pumila) is a locally widespread tree common to the southwestern US. It is a mid-size tree that can reach 70 feet tall. At Watson Woods Riparian Preserve this tree out-competes native cottonwoods, willows, ash, boxelder, and walnuts to the extent that Prescott Creeks has listed it as a Priority 1 species on
In April, Prescott Creeks will once again make a push to control invasive weeds in the Granite Creek Watershed. Our American Conservation Expereince (ACE) crew will be here for 8 days to help us make another push at improving habitat. Not sure what an invasive weed is? Often thought of as just “weeds” these are
Dalmation toadflax is a wide spread invasive. The extent of it’s spread can be seen in this map from the Natural Resources Conservation Service. Originally brought to North America from the Mediterranean region of Europe as an ornamental, Dalmatian toadflax is currently found in at least 34 states in the U.S. and most of the
Like other creeping perennials, the key to Russian knapweed control is to stress the weed and cause it to expend nutrient stores in its root system. An integrated management plan should be developed that places continual stress on the weed. Currently, the best management plan includes cultural control combined with mechanical and/or chemical control techniques.
This is often a favorite to hate in the central Arizona highlands. Knapweed is a pioneer species found in recently disturbed sites or openings. Once it has been established at a disturbed site, it continues to spread into the surrounding habitat. This species outcompetes natives through at least three methods: A tap root that sucks up water
Malta starthistle (synonyms: Napa starthistle, tocalote) is an annual invasive weed with foliage and winged stems that are grayish to green in color. Its thistle-like appearance is similar to yellow starthistle (C. solstitialis), but Malta starthistle is distinguished by smaller yellow flowers and longer seedpods that are armed with relatively short spines (less than 1/2
From the CA Extension offices: Sweet resinbush (Euryops subcarnosus) is an exotic species from South Africa that was introduced in Arizona during the 1930’s.It was brought here in hopes that it would provide forage for livestock and aid in slowing soil erosion. Potted plants were sent to Civilian Conservation Corps camps in 1935 where they
From the Wikipedia entry on this invasive weed: Onopordum acanthium (Cotton thistle, Scotch thistle), is a flowering plant in the family Asteraceae. It is native to Europe and Western Asia from the Iberian Peninsula east to Kazakhstan, and north to central Scandinavia, and widely naturalised elsewhere. It is a vigorous biennial plant with coarse, spiny
Tamarix is perhaps one of our bestter know invasive species. It is found widely throughout the Southwest. The description below comes from Wikipedia, where you can read more in depth on the subject. They are evergreen or deciduous shrubs or trees growing to 1–18 m in height and forming dense thickets. The largest, Tamarix aphylla, is an evergreen tree that can grow to 18
The priority species for the Upper Granite Creek Watershed are: Dalmation Toadflax (Linaria dalmatica), Diffuse Knapweed (Centaurea diffusa), Russian Knapweed (Acroptilon repens), Spotted Knapweed (Centaurea maculosa), Malta Starthistle (Centaurea melitensis), Sweet Resinbush (Euryops subcarnosus), Scotch Thistle (Onopordum accanthium), Common Teasel (Dipsacus fullonum), Saltcedar (Tamarix ramosissima), and Russian Olive (Eleaganus angustifolia) Over the next few days
Prescott Creeks often talks about invasive weeds, but what are they and why are they a problem in our area? The U.S. Fish and Wildlife Service says the following: An exotic species is any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that
Join Prescott Creeks on an invasive species removal spree. We’ll teach you about the invasives, why they’re the bad-nasties we want out of the watershed, what they’re doing to the habitat and water quality, and what you can do about and to them. Then, we’ll take up all of their space by seeding native grasses.
The Urban Habitat Improvement through Invasive Species Removal project will improve riparian habitat conditions along urban creek reaches in the upper Granite Creek Watershed through the control and removal of target invasive vegetation species. The Granite Creek Watershed, located in central Arizona, is an important headwater of the Verde River, one of Arizona’s few perennial
This summer, led by Prescott Creek’s Jay Crocker, volunteers successfully removed many invasive noxious weeds such as spotted knapweed from Watson Woods. But this is not solving the weed problem because several species are widespread throughout Prescott. Many grow along creeks and spread in the area and throughout the watershed. The seeds blow in the