Rosebay Willowherb


I moved into a new house last year and inherited a "blank canvas" of a garden.  The house is a new build (built on what was previously farmland) and is on the edge of the development with a drainage ditch beyond the back fence.  This spring I have noticed a particularly invasive plant cropping up at frightening speed.  After lots of research online it appears to be Rosebay Willowherb.

 It is spreading into my newly created borders at alarming speed and even popping up in the lawn.  I am digging it up almost as fast as it appears, which is pretty much on a daily basis, but it is impossible to remove all the roots (I have clay soil which makes it harder).

Any tips of getting rid of it?  The source seems to have originally come from undeveloped land beyond my boundry fence, so I cannot access this area or apply weed killer to land which is not mine. Apart from weeding regularly, what can I do?  I am concerned about any possible effects on my home should it come up as far as the house - can it damage brickwork or structures?  If I can manage to control it this year, will it return just as bad next year?  Help!




  • Gold1locksGold1locks Posts: 499

    It spreads via underground rhizomes as well as from seed. It is not like Japanese Knotweed but is very vigorous. Glyphosate asap and then again a few weeks later. 

  • I am sure that it won't damage your house. The seeds are very floaty in the wind, so you will get a new contribution each year I am afraid. You will develop your own coping strategies. Where I live is dandelion alley... we all have a cross to bear. at least it's not bindweed or ground elder.image

  • PinklepurrPinklepurr Posts: 10

    Thank you!

    I should have said that I'd prefer not to use chemicals as we have a cat and there are several next door too, who roam into our garden frequently.

    Knowing it will not cause damage to buildings is reassuring.  I actually had a nightmare last night where it took over the entire garden!  Stupid I know!

    I think if I can contain it by regularly weeding that will be ok, and next year I shall be on the alert earlier than I was this year.

  • Gold1locksGold1locks Posts: 499

    This is an extract from the above article. 

    Seeds have a plume of hairs and are wind dispersed. It has been estimated that 20 to 50% of seeds may be carried 100 m by the wind and some could potentially travel over 100 km. Rosebay willowherb also spreads by the horizontal roots on which adventitious buds develop. The roots extend by up to 1 m per year and spread well beyond the aerial stems. Expansion is limited where soil fertility has declined.

    Established colonies of rosebay willowherb may persist for long periods. On sand dunes in Holland, stands 35 years old have been identified. Fragments of root can produce adventitious buds within 3 weeks. Longer fragments are more successful at regeneration and sections shorter than 8 cm are unlikely to produce shoots. Even pieces of 20-year old roots can produce buds following soil disturbance. 

  • FairygirlFairygirl Posts: 19,692

    It's very invasive but if you keep pulling and hoeing it you will keep on top of it. My last house was rural and it was everywhere including the banks of our pond. We had a large wild area and we used Resolva regularly as well as mowing. It's annual and perennial and they can look quite different.  I think the previous owners thought it was a pretty flower...image Each plant can produce thousands of seeds so as soon as they get to flowering stage pull them out.  Good luck!

  • Roy HillRoy Hill Posts: 55

    I have rosebay willowherb, bramble, nettle, field bindweed, bracken, ragwort (and others). I'm not on a new housing estate and the garden is therefore a bit 'rambling'. Admittedly, I have the luxury of a large-ish garden and can afford to let some indigenous plants flourish in selected areas. As someone else hinted - there are worse. Ground elder, japanese knotweed and (dare I say it) himalayan balsam. Be sparing as possible with glyphosate - it does affect insects at higher doses. I've seen a wasp curl its toes in a solution. Also be aware that there may be other stuff mixed in which you might not want to knobble. There are quite a few variences on the view of a 'blank canvass'. Rosebay willowherb is a larval foodsource for more than a handful of moth species.

    Your choice in the end.

  • It is the main food source for the  Adult Elephant Hawkmoth,which is very beautiful

  • Rosebay Willow Herb is a good source of food for the Honeybees, Bumblebees And as Daveandtrish says the Elephant Hawkmoth, If its not causing a problem leave it alone. But if it grows where I don't need it I just pull it up. 

  • nutcutletnutcutlet Posts: 24,027

    I'll keep my rosebay willowherb, I wouldn't want to e without these



  • Brilliant I wish more people would give a little more thought to our beautiful wildlife,I've always thought a lot of what some people call weeds are actually wild flowers in their own right and very beneficial to our wildlife,my wife and I over wintered an Elephant Hawkmoth catterpillar and last night I had the pleasure of releasing one just like the one in the picture after I had the amazing experience of her sitting on the back of my hand for a minute or two before taking flight,it was magical.

    Regards,David and Trish 

  • nutcutletnutcutlet Posts: 24,027

    You're right Dave and Trish. Lots of planting for butterflies that will be happy with almost anything. But the caterpillar stage is called a pest and not catered for.

    My rosebay willowherb is coming along nicelyimage

    as are many other 'weeds'.


  • Hello

    Someone has cut down a patch of rosebay willowherb , great willow herb, aster, and many other wildflowers. They wish to use the area as acar park

    Will these plants grow back if they have been cut to the ground. This was an area of land being secured for wildlife which it will be , just would like to know what damage has already been done

    Thankyou for any advice

  • nutcutletnutcutlet Posts: 24,027

    I should think all be fine, the perennials die back in winter anyway and annuals should have seeded now. Managed meadow areas are always cut back at some point in the year depending on what's in them

  • I don't think its possible to stop  Rosebay willow herb from propagating, the seeds just blow everywhere.

    It is quite easy to pull up though.

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