Field horsetail
Botanical name
Equisetum arvense
Family
Equisetaceae (horsetail)
Also known as
Common horsetail, scouring rush
Where is it originally from?
Temperate northern hemisphere
What does it look like?
Erect, colony-forming, summer-green perennial, primitive fern-ally (<10-80 cm) with extensive, deep, freely branching rhizomes with round tubers. All aerial parts die back in winter. Stems are of two types: (1) sterile stems (10-80 x 1-5 mm diameter) are green, jointed, hollow, ribbed or grooved, very rough to touch (containing silica), with lateral branches in whorls and leaves (10mm) which are green sheaths. Resembles a pine seedling, and (2) fertile stems are pale brown, shorter with larger joints, unbranched, with pale brown 14 mm sheaths, appear in early spring before sterile stems, produce conspicuous (4-40 mm long) terminal cones, and die quickly after shedding spores. Spores are seldom produced in New Zealand.
Are there any similar species?
Rough horsetail (Equisetum hyemale) is very similar but rare, it has slender, taller, very rough, asparagus-like spears with black rings, no leaves, no (or very occasionally few small) branches, cones on green stems. E. fluviatile (rare).
Why is it weedy?
Matures and spreads quickly, forming dense, long-lived mats. Tolerates flooding to dampish-dry soil, warm to very cold, wind, and deep burial but is intolerant of dry soils. Toxic to stock.
How does it spread?
Rhizomes and tubers are spread by water, soil and river gravel movement and contaminated machinery. Sources include rivers, roadsides, pasture, and gardens, where it has been found being grown as a homeopathic remedy.
What damage does it do?
Forms pure stands in wide range of damp habitats, preventing the seedlings of native species from establishing. Blocks and alters watercourses, causing flooding.
Which habitats is it likely to invade?
Bare land, river systems especially silty, sandy and gravelly sites, and streambanks.
What can I do to get rid of it?
Note: You may be required to report this weed in some regions. Check the status on your regional council website prior to control.
1. Physical removal - Hand pull or dig out entire plant - Ensure all root material is removed to prevent regrowth. Burn or dispose of all plant material and contaminated soil to refuse. Ensure the material is properly contained/bagged and secured to avoid any potential plant material escaping and spreading.
2. Cut and paste: Cut the stem/trunk as close to the ground as possible and cover the entire stump with herbicide as soon as possible after cutting. Apply metsulfuron gel (10g/L strength).
3. Foliar spray - Apply metsulfuron herbicide (600g/kg active ingredient at 5g/10L knapsack or 20g/100L gun and hose) plus organosilicone penetrant (3ml/L) OR picloram/triclopyr herbicide (picloram 100g/l and triclopyr 300g/l active ingredient at 6ml/L) plus organosilicone penetrant (1ml/L) to thoroughly wet all parts of plant. Note: picloram/triclopyr herbicides are ‘grass friendly’ but overspray will kill other (desirable) broadleaf plants. Picloram and metsulfuron have residual activity in the soil which may leach and kill other plants. Do not use under and around other (desirable) broadleaf plants. NOTE: These herbicides are not for use over or near water bodies or wetlands
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and directions for the purchase, use and storage of the product, are followed and adhered to.
What can I do to stop it coming back?
Resprouts constantly from rhizomes and tubers. Resistant to most herbicides, extremely difficult to kill. Lowering watertable can slow rate of spread.
Check out what the Weed Wizard has to say in the video below
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