Killing Onion Weed

Onion Weed is a persistent, perennial bulb-type weed. Easily detected by the pungent onion-like odour that it gives off, especially after mowing, it is a cosmopolitan weed the bane of gardeners’ lives all over the world. One of the most difficult weeds to eradicate, it can in some cases be near impossible to completely kill Onion Weed. Digging out the weeds is not advised as, due to the tiny bulbs attached to the bottom of the plant’s main root, it will only serve to aggravate the situation.



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How to Kill Onion Weed

There remains two effective ways to kill onion weed however, the use of a glyphosate based weedkiller, such as Roundup, or covering the area under a sheet of black plastic. The first solution is the most effective and straightforward, if a little time consuming. Although the entire area around the Onion Weed(s) could be treated, this will kill all plants in the area, thus it is advised to treat each Onion Weed individually, with a small brush for example. However, due to the prolific nature of Onion weed this can be incredibly tedious and time consuming. The second solution proposed is not without its faults however. Covering the weed with thick, opaque, preferably black plastic on a hot summer’s day effectively ‘cooks’ the soil underneath it, though the plastic is a rather ugly addition to a garden and needs to stay there for weeks to be fully effective. Furthermore, the plastic prevents moisture from getting to the soil underneath, which can leave the area in question dry and barren meaning the soil either needs to be replaced or a wait of around 1 – 2 years for the earth in question to get to its original nutritional levels.


Other topics related to : How to Kill Onion Weed

Killing weeds

Weeds on the lawn

Weed killer for grass

Lawn Weeds Identification

How to kill weeds

How to kill weeds permanently


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3 simple steps

  1. Measure the area you need to cover Use our quick and easy to use size calculator
  2. Watch our easy to follow video tutorials View our video tutorial library
  3. Buy the right Roundup for you Select your dispenser and purchase here



What are the origins of Roundup?

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Roundup was first developed for the agricultural industry to help farmers overcome large-scale problems with weeds. This same science and technology has been applied to create a range of weed killing products ideal for domestic use. So, rest easy in the knowledge that you’re using the weed killer the professionals use.


Can I put it on stronger? Will that work better?

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We have carefully calculated the best rates at which to apply for each type of weed problem. Applying at a strong rate is not recommended and will not result in better performance. Please ensure that you read the label before use and use pesticides safely.


Does the Concentrate need using up straight away after mixing?

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It’s always good practice to only mix up what you need for that treatment, but you can retain the unused solution for up to a week, since a gradual loss of activity will occur. Make sure that you store any weedkiller safely away from the reach of children and pets.

Why to choose Roundup Weedkiller


Use the strongest weed killer to get rid of tough garden weeds

Thanks to glyphosate, Roundup has an effective weed killing action!


Buy a cheap, but very strong weed killer for your garden maintenance

Roundup Garden products are available in all garden centers.


Use the strongest weed killer to get rid of tough garden weeds

Thanks to glyphosate, Roundup has an effective weed killing action!

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