An Invasive Willowherb to Watch For

This plant masquerades in a familiar body plan, passing by many gardeners and land managers unnoticed

Most of us gardeners have a right read on which industrial plant in our gardens are baffling — which we often bear on to as weeds . Typically these plants make seasonal show , like thecommon mallow(Malva neglecta ) that germinates in my home plate hayfield with an telling , if distressful , degree of persistency . Each year I weed all that I can , excavate their unchewable , white taproots from the backyard cadaver . And each twelvemonth as dirt temperatures draw close those appropriate fortomato planting , a brisk craw springs anew from the seed bank left before I began weeding the space . now and then , however , a young undesirable plant life urinate its debut on our horticultural level .

A new invasive to watch for

In short , I require to utilise this month ’s post to fetch aid to this emerging encroacher . It has yet to spread wide through our region but is of concern , and it has been successful in take in a footing on the Colorado Front Range . The first prescribed Colorado record I could find of this plant , hairy willowherb(Epilobium hirsutum , Zones 2–9 ) , which is native to Africa , Europe , and parts of Asia , came from the early 2000’s . A function produced by the Colorado Department of Agricultureflags the plant as present in at least eight counties .

view how many of today ’s neighborhoods have rude areas that often double as retention position for locality overflow , this plant may not be far from you . Keep your centre flake off for it , and if you come up it , take appropriate action to obviate it ( say , if the plant is on your property ) , or notify land managers who can do so ( if it is on public property ) .

If you see what you guess might be this plant but are n’t sure , yourlocal Colorado country extension officeorcounty weed management officeshould be able to help oneself . Alarmingly , I ’ve even found the specie making a backstage show in greenhouse green goddess that its seed had blown in to ( yikes ! ) .

I have been able to find write up of hirsute willowherb in the first place from the Colorado Front Range , where wind - spread seeds helped fuel its relatively speedy spreading . Just a few specimen are cover from the Wasatch Front and Heber City orbit in Utah as well as the Idaho - Washington borderline . It is a “ List A ” noxious skunk in Colorado .

Plant Profile

Scientific name : Epilobium hirsutum

Common names : Hairy willowherb , giant willowherb , codlins - and - cream

Zones:2 – 9

Size:3 feet wide-cut and 3 to 6 feet tall

Habitat : Wet soil , riparian areas , and wetlands .

Native Range : Africa , Asia , and Europe

Diagnostic features

Look-a-likes

Of the native species , few attain the height of hairy willowherb , and fewer still form monocultures . Fireweed ( Chamerion angustifolium , Zones 2–7 ) is a indigene that may be this works ’s skillful regional look - a - like and grow primarily at high elevation where it can mold monoculture in sick sites . So far , hairy willowherbhas not designate that it can colonize eminent portions of our neighborhood , further helping to separate the two species . Fireweed also lacks the dull , soft hairs of hairy willowherb and grow efflorescence in a dumb , single spike , rather than a loose clustering . While wickup and hairy willowherb have interchangeable flower size and color , fireweed keeps spaces between flower petals ; hairy willowherb petals touch or overlap to imprint a loving cup shape .

Fireweed is a aboriginal look - a - the likes of to hairy willowherb . photograph : H. Zell viaWikimedia . CC 3.0

Hairy willowherb ’s petals touch , making it easy to differentiate from giant willowherb . Photo : H. Zell viaWikimedia . mil 3.0

Management

bar is the good direction for this plant . Maintaining healthy works residential area , whether in your garden or wild spaces , reduces the chances of an invader feature the chance to get a beachhead . Once present , pocket-sized population of hairy willowherb can be hand dug , but broken rhizome pieces will resprout , requiring several rounds of comprehend . prevent flowering by cutting or mow stand can decelerate the bedspread of this plant life . Larger , established stands are well manage by professional , as chemic controls are the only test method on such a shell . Regular scouting after eradication is require to see to it that plants do n’t reestablish from seed or rhizome opus in succeeding years .

watch more about managing invasive plants :

name and Controlling Common Invasive Plants

withdraw These Regional Invasive Plants

How to Get Rid of Invasive Plants

Bryan Fischer lives and gardens at the intersection of the Great Plains and the Rockies . He is a horticulturist and the curator of plant ingathering for a local botanic garden .

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Hairy willowherb plant is invasive in the USA

Hairy willowherb growing in a field.Photo: Byran Fischer

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hairy willowherb growing

Hairy willowherb growing in a field.Photo: Byran Fischer

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Hairy willowherb foliage.Photo: Bryan Fischer

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