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Deadfast Concentrated Weed Killer Sachets2022 Review

Well, that’s quite a name! I did laugh over the title of this product which gives no illusion as to what it does.

Deadfast Concentrated Weedkiller kills most perennial weeds and comes in liquid sachets. This is much like the plastic tubes Weedol Ultra Tough Weedkiller is dispensed from and a user-friendly no-mess way to deal with poison.

It has 12 sachets to cover 720 m2 which is a large space and Deadfast helpfully indicates it’s an area that 6 parked cars will cover.

Deadfast Concentrated Weed Killer Sachets Review

  • Where to buy
  • Our Scoring
    Ease Of Application
    Speed Of Results

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Our Verdict of The Deadfast Concentrated Weed Killer Sachets


Ease Of Application

You must wear gloves when cutting off the edge of the weedkiller sachet. It’s easy to squeeze or dribble the product onto your fingers which I did several times despite being extra careful.

Once the packet is in the watering can or the sprayer it’s simple to add the litre of water needed to mix up the solution. I like these no-mess no-measuring weedkillers.

There are two ways to apply this weedkiller. As above in a spray or watering can or directly from the packet onto roots in one concentrated hit. I used it in a sprayer and directly on the trunk of a recently cut away ceanothus.

The instructions say you have to cut back the plant so part of its trunk is exposed near the ground, then pour the content directly on. As I said it’s important to wear gloves because it spills.


Yes, it worked and killed the weeds, but it wasn’t especially fast. It’s comparable with other weedkillers I’ve tested out so not an individual claim to fame.

Creeping buttercup shrivelled despite a downpour, and dock leaves were killed off too. Roots took a bit longer and it was around 3-4 weeks before dug up roots showed any signs of weedkiller effect.

I tried a concentrated bag on an old ceanothus that I’d cut to the ground and was not looking forward to digging out. After a month it was looking a little browner but as yet, there’s very little to show. I’ll report back on what happens.


Speed Of Results

The weeds wilted within a day and actually looked sick a few hours after application, but it was a good 6-7 days before they started browning enough for me to notice actual evidence of the weedkiller working.

After a month the roots were shrivelling so I’d say this weedkiller works just as well as others and has the advantage of being measured out in advance.


First off, the sachets come in a tough plastic container so you aren’t saving any plastic over say Resolva or Roundup for example, but this container can be used to store other things afterwards as the weedkiller is contained in individual sachets.

The main ingredient is glyphosate which is toxic to bees and pondlife so this isn’t wildlife-friendly. Please do cut flower heads off weeds first, especially dandelions which are bees’ first food after hibernation.

Pets and children can use the area safely after the liquid has dried. It takes up to an hour for all of the liquid to dissipate and longer for direct application of the undiluted product. That took all afternoon to dry out because it was in a shaded area.



4 2.875

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The Cheapest Deadfast Concentrated Weed Killer Sachets Found Today

Prices last updated: 21 June, 2022

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