What's bugging you? Mar. 1, 2017
By Jim Leser
Published Thursday, March 2, 2017 7:56 am
My records show that I have already covered five of the 10 most unwanted weeds in the garden series. The next one is the redstem filaree, a class "C" noxious weed in Colorado.
A widespread, early spring, rather inconspicuous plant with a pretty flower, redstem filaree is sometimes considered a threat to agriculture but more often it is a boon to wildlife. Let me explain. While this weed can outcompete native grasses in rangelands and pastures, and can certainly invade our lawns and gardens, it is grazed by many animals including cattle, sheep, goats, deer and even tortoises. It is also edible for us to use in salads or cooked like spinach.
Redstem filaree is in the geranium family and has the Latin name, Erodium circumtarium. It also goes by other names such as storksbill and cranesbill. It gets these names because of its beak-like seed structure. It grows as a ground-hugging rosette with divided leaves, taking on a feather-like or fern-like appearance. Stems are hairy and red. The weed's root system is shallow with a taproot and secondary fibrous roots. Its small flowers are purple-pink, borne in clusters of two or more. Fruit is five-lobed and long beaked.
This is an introduced weed from Europe or Asia but is now common worldwide. It was probably introduced to California by the early Spanish explorers in the 1700s. Redstem filaree is primarily a winter annual with a single generation, reproducing solely by seed. Germination occurs from late fall to early spring. I have a few plants growing on bare ground areas in my yard right now. They are among the earliest blooming plants in Colorado, flowering as early as February to April. This weed has been found growing at elevations from 1,000 feet up to 7,500 feet.
Storksbill prefers bare ground and is quite drought tolerant. It gets its competitive edge by covering up areas early, before other plants can become established. It is often found competing in rangeland areas that typically consist of cheatgrass, sagebrush and rabbitbrush. It prefers loose soil but can grow in clayey soils and under alkaline conditions.
The main objective of management of this weed is to prevent seed production. But since seeds can live a long time, it can take several years before control is truly achieved. Cultural control would entail planting grasses or mulching bare ground areas. Mechanical control is simply hoeing or digging up plants before they produce seed. There is no biological control available at this time. Chemical control would entail the use of a broadleaf herbicide such as 2,4-D or 2,4-D + dicamba.
From my perspective, this is an interesting little weed with pretty flowers, a distinctive seed and as a bonus is utilized for grazing by many animals. I take a let-live position with this weed unless it invades my lawn or starts crowding my garden plants. This has got to be one of the least noxious weeds we have in Colorado gardens.
Jim Leser retired to Cedaredge in 2007 after a career with Texas A&M University Extension in entomology. He is a member of the Cedaredge Tree Board and a Colorado Master Gardener.