As winter sets in, it’s time to take a look at your garden and clean up any remaining Japanese knotweed. This invasive plant can damage your property and spread rapidly, so it’s important to remove it as soon as possible.

Know what to do ahead of your winter clearance of Japanese knotweed and be prepared before the Spring when comes back aggressively.

In this blog, we look at what you should do with this invasive weed during winter.

What does Japanese knotweed look like in the winter?

The weed’s heart-shaped leaves become brown and fall off the plant when the temperatures drop and the winter days take control. Its green canes will wilt and degrade over time, turning brown.

The weed is still standing, which gives people false hope that the herb is indeed dead. When winter is over and spring is on its way, you’ll observe crimson or purple shoots emerging. These shoots will develop at an incredible rate, eventually reaching a height of 3 metres.

The Japanese knotweed and bamboo are similar in appearance, although they are a deeper shade with stems that are hollow and light.

Japanese knotweed stems in winter still consume a garden even when dead
Japanese knotweed stems in winter still consume a garden even when dead

Can you treat Japanese knotweed in winter?

Herbicides can’t be used to destroy Japanese knotweed in the winter since the plant needs to be in leaf. A dig-out of the afflicted area is the remedy you’re looking for at this time of year.

The canes will slowly degrade during the winter, and the plant’s remains will litter the ground. Other plants will be unable to grow on that patch of soil due to the rotting remains of Japanese knotweed.

Can You Eradicate Japanese Knotweed in Winter?

Anyone whose property or surroundings have been afflicted by Japanese knotweed for the whole year may be relieved at this time of year since the harmful plant has not only ceased growing but looks to have perished entirely. Is this the end of the problem, and you can go about your business instead of fighting this highly invasive, non-native species that are wreaking havoc on properties across the UK?

Unfortunately, the answer is no. Although Japanese knotweed may appear to have perished by the time winter arrives, it has just gone dormant, surviving on the energy stored in its massive subterranean rhizome network during the coldest, darkest months of the year.

If you have Japanese knotweed on or near your property, it will appear as leafless, brittle bamboo canes that have turned brown and are devoid of life.

The vast rhizome root structure of Japanese knotweed, on the other hand, is very much alive and waiting out the winter before sending up additional shoots to inflict all sorts of destruction. So, can you remove Japanese knotweed in the winter, or should you wait till the plant grows in the spring or summer?

Dense coverage of Japanese knotweed as it dies back during winter - identifying Japanese knotweed in winter
Dense coverage of Japanese knotweed as it dies back during winter – identifying Japanese knotweed in winter

Can you remove Japanese knotweed in the winter?

Removing Japanese knotweed in the winter is possible, but it’s a very bad idea if you want to completely eradicate the plant. This is because any attempt to cut down Japanese knotweed in winter will be useless, as it’s a deciduous plant and will not shoot up new growth until spring or summer.

Additionally, the root system of Japanese knotweed is so invasive that it often requires several attempts at removing the plant before it’s finally eradicated from the property. In other words, killing Japanese knotweed in winter is not effective.

Can you kill Japanese knotweed in the winter?

Unfortunately, killing Japanese knotweed in the winter is not a viable solution, as the plant is still very much alive and will continue to grow and spread if left untreated.

Let’s take a closer look at why cutting down Japanese knotweed in the winter will not help to completely kill off this invasive plant. Japanese knotweed is a deciduous plant, which means that it loses its leaves in the winter and does not grow new shoots until spring or summer.

As mentioned above, the only time it’s possible to successfully kill Japanese knotweed is during late spring or summer before it starts shooting up new growth. During this time, dig up as much of the root system as possible and immediately spray with herbicides to ensure that it doesn’t regrow.

In conclusion

However, even if you are successful in completely killing off Japanese knotweed, it’s important to keep an eye on the property for future infestations. Japanese knotweed can grow back from a small piece of the root, so it’s important to keep an eye out for any new growth.

If you do see any new growth, it’s important to take action right away. You can either try to remove the weed manually or use a herbicide to kill it off. However, be sure to read the label carefully before using any herbicide, as some can be harmful to plants and wildlife.

If you’re not sure how to get rid of Japanese knotweed or you’re afraid of doing it wrong, it may be best to call in a professional.

Want to know more about the winter clearance of Japanese knotweed?

Knotweed Removal aims to provide the most up-to-date information, help and advice for YOU to make informed decisions. If you are unsure or uncertain about how to proceed, please reach out to us and we will gladly come back and advise you as best we can.

Governmental advice can be found here and the UK law covering the removal of Japanese Knotweed as stated under the Wildlife and Countryside Act 1981 can be found here.

The best means to contact us is via our email –

Do not forget we have a library of blogs covering many areas relevant to Japanese Knotweed, our free downloadable How-to Guides and Product Reviews on the latest methods being employed to eradicate or remove Japanese Knotweed.

Knotweed Removal, UK

Bestseller No. 1
Bayer Garden 2 x Path, Patio & Drive Weed Killer & Watering Can Set - 3 x 8g Sachets per pack treats upto 75sqm - Kills Ground Elder, Nettles, Docks, Couch Grass & Japanese Knotweed.
  • This exclusive twin pack and 9L Watering Set is everything you need for clearing weeds from paths, patios and rives including areas of tarmac, concrete and block paving.
  • Kills tough weeds and their roots including: Ground Elder, Nettles, Docks, Couch Grass, Japanese Knotweed, Brambles, Bracken & Ivy.
  • Each box contains 3 x 8g Simple ready measured soluble doses and treats up to 75sqm. Apply at any time when weeds are showing green leaf and are actively growing.
  • Sold with our durable 9L or 2 gallon capacity galvanised steel watering can with removable brass rose. Colour cannot be guaranteed. Watering can will be randomly picked and despatched.
  • Keep children and pets away from treated areas until the spray has dried.
Bestseller No. 2
Roundup Tree Stump Weedkiller, Super Concentrate 250 ml
  • Kills ivy japanese knotweed, saplings, brambles and nettles to the root
  • Kills up to 16 tree stumps
  • Contains a reusable pipette for specialist treatment of japanese knotweed
  • Kills the roots so weeds don't come back
  • Degraded in the soil by micro organisms
Bestseller No. 3
Weedol 011005 Pathclear Weedkiller Liquid Concentrate, 6 + 2 Tubes
  • Unique dual action fomulation, kills weeds to the root and prevents new weeds growing for up to 3 months
  • Ideal for paths, drives and patios
  • No measuring or mess - just add water
  • Creates an invisible barrier that prevents new weeds for up to 3 months
  • Children and pets need not be excluded from treated areas (once dry)
Bestseller No. 4
RootBlast - RootBlast 360 Glyphosate Home Garden Weedkiller - 1L Bottle with Integral Measuring Device Pair - Includes Pair Of gloves - 1L Makes Up to 50L
  • WEED KILLER CONCENTRATE: Rootblast's strong weed killer is both super-concentrated and tough on most broad leaf and grass weeds. It's specifically designed to bring you the best results by using systematic herbicide technology. It targets weeds from the inside and kills them at their underlying roots, preventing any future growth
  • GLYPHOSATE WEED KILLER: For optimal weed control, Rootblast have created a concentrate weed killer that contains 360g/l of glyphosate. Glyphosate is a broad-spectrum systemic herbicide and crop desiccant that is used by famers. It kills and destroys the weed without affecting the crop. By using glyphosate, Rootblast's weed killer is stronger and more effective than most other weed killers on the market
  • GLYPHOSATE HERBICIDE: This powerful and effective weed killer is designed to target weeds such as dandelion, grasses, docks, nettles, willowherb, bindweed, woody brambles, tree stumps, ivy and more. After applying Rootblast's heavy duty weed killer, the first signs of weed control are visible when the weed leaves yellow - this can take anywhere from a few days to up to 2-4 weeks. From this 1 litre bottle of glyphosate herbicide concentrate, you can make up 50 litres of product when it's diluted
  • DOCK, GRASS & DANDELION KILLER: Alongside this industrial strength weed killer, you'll receive a pair of protective gloves as well as the integral measuring device attached to the bottle. The gloves provide you with protection to ensure your experience is as easy and safe as possible. The integral measuring device is an inbuilt measuring cup, simply remove cap and carefully squeeze the container until the cup is full
  • TOTAL PROTECT WEED GARDEN SPRAY: This easy to use product is available as a ready to use tough, concentrated weed killer that comes with a integral measuring device attached and protective gloves. Use by professional garden and farmers, this product can tackle your weed problem and kill the weed from the root - the ultimate weed killer!
Bestseller No. 5
Rootblast Glyphosate Weedkiller 4 x 100ml Concentrate with 5L Pump Sprayer
  • For use on unwanted vegetation and areas not intended to bear vegetation
  • Contains 72 g/l glyphosate for effective control of annual and deep-rooted perennial garden weeds, including grasses*, docks, nettles, willowherb, dandelion and bindweed. Also suitable for woody brambles, tree stumps and Ivy.
  • Coverage up to 66sqm per sachet

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