Telephone: 01892 782087
Mobile: 07971 671580
Coombe Lane, Wadhurst.
East Sussex. TN5 6NU

Weed Killer

Coombe Farm Weed Killer is the same concentration of active ingredient (Glyphosate) found in Roundup Ultra or Roundup Pro Biactive  - both can cost up to £45 per Litre. Ours is cheaper and it is 3 times the strength of Roundup GC 120g/L.  One Litre of chemical provides enough concentrate to spray 3000m2 of easy weeds like grass or 1500m2 of really difficult weeds once it is diluted with water - just like Roundup. To give you some idea of area - a football pitch is 4050m2.

The chemical has "no sell by date" so as long as you keep it away from extremes of temperature it will do you for several years if you only have a small patch to treat. The weedkiller comes complete with both written and pictorial instructions to show how much to use depending on the method of application.  

Using glyphosate in the spring and autumn can provide you with a very cost effective solution to weed control as well as saving you a lot of time getting rid of plant material in the spring through digging.

Spraying Tips

When and where should I spray?

Glyphosate at a concentration of 360g/litre is a powerful herbicide which works very efficiently in all areas including gardens. Points to note are:When spraying around roses and other plants please make sure you do NOT get spray onto the foliage of desirable plants as it will destroy them. This is a NON-selective herbicide.

  • You can spray an area BEFORE cultivating as well as straight after sowing when the seeds have not yet germinated. This is not a PRE-EMERGENCE spray and will only effect plant tissue through absorption.
  • Re-seeding of lawns can be done by spraying of the old lawn, leaving it for a week, and then re-sowing with new grass seed. This gives the spray time to act.
  • Some weeds are harder to kill than others. Brambles and thistles at early stages of development will need a much higher concentration of spray than grasses. This can be either by spraying longer or by spraying with a higher concentration.
  • Adding detergent like washing up liquid to your sprayer helps the spray penetrate the leaf.

Ideal weather conditions 

Spray when there is little or no wind to avoid drift.

  • Spray in the evening or late afternoon as this is when plants draw down sugars and consequently the glyphosate too!
  • Do not spray when raining as run off will occur and the effect will be diluted if not rendered totally in effective. Allow 1-2 hrs of setting time should you be worried about the weather.
  • Is usually used between February and November although outside these times it can be used when conditions are dry e.g. we spray around Christmas trees in December and January.

How does it work?

  • Glyphosate-based herbicides all work on the same biochemical principle - they inhibit a specific enzyme that plants need in order to grow. The specific enzyme is called EPSP synthase. Without that enzyme, plants are unable to produce other proteins essential to growth, so they yellow and die over the course of several days or weeks. A majority of plants use this same enzyme, so almost all plants succumb to Glyphosate.

How to use the chemical safely

  • Read the recommend dosage for your method of application.
  • Wear gloves and suitable protective clothing to avoid skin contact as well as eyes.
  • Keep out of reach of children and pets.
  • Do NOT spray in ponds as it will kill your pond life.
  • Wash your hands before eating.
  • Do not spray water troughs etc that maybe used by animals for drinking purposes.
  • If you do get some in your eyes then rinse with plenty of water and consult a doctor.
  • Store away from extremes of temperature.
  • It is neutralised on contact with the soil so it is SAFE FOR PETS AND CHILDREN.

Area covered and safe disposal

  • This product is safe to use in both garden and agricultural applications where 5Litres /Ha is the recommend dose for easy weeds and 7 Litres/Ha for difficult weeds such as nettles, thistles and docks. A Ha is approx 2.5 acres  or if you like m2 then its 10,000m2
  • Dispose of the container in a sensible way. Rinsing it out beforehand with water will minimise any unnecessary pollution.

Difficult weeds - how do you get rid of them?

Horsetail or Marestail
(Equisetum Arvense)

This is a difficult perennial weed, which grows in a wide variety of places. It
has two types of growth, in spring brown asparagus-like shoots appear with cones at the tips producing spores. Later the more familiar thin green, branched
stems appear and these remain until the winter. Both are produced from creeping underground rhizomes, which go down about 1.5 metres. Glyphosate can be used but firstly you must crush the stems to break the waxy surface and then applying Glyphosate in a neat form, ie no dilution , with a small paintbrush. Glyphosate has the advantage of keeping the plant alive whilst the chemical travels from one cell to another in the plant before killing it. Repeat applications will kill it after 5 months.

Hedge and Field Bindweed
(Calystegia Sepium and Convolvulus Arvensis)

A herbaceous perennial, spreading bycreeping underground stems, which root readily. Before the use of chemicals such as glyphosate digging it out was the best way to control it. The problem with this method is that every small piece of root left turned into a new plant. With the roots being brittle it is almost impossible to remove the entire root, so inevitably after a short period of time the problem returns, only larger. As with Horsetail it is best to apply the glyphosate in its neat undiluted form with a small paintbrush directly to the leaves. A couple of application should be all that’s needed.

Couch grass (Dog's Grass, Twitch)
(Agropyrum Repens, syn. Elymus Repens)

Couch grass is a perennial grass with creeping underground stems with
small fibrous roots at every joint. Glyphosate is extremely effective against Couch
grass but may need a second application. Normally takes about a month to die of completely.

(Rubus Fruiticosus)

A fast growing weed that colonises an area quite rapidly. The best way to get rid of large areas of brambles is to cut them down and then spray the emerging leafed shoots with Glyphosate. You will need to repeat the treatment as it’s a really tough one to control

Japanese Knot Weed
( Polygonum Cuspidatum)

This is perhaps the hardest weed of all to control and a treatment programme needs to be set up. Spray with Glyphosate in the autumn as it starts to die back for the winter and then again when the plant re-shoots in the spring with two or more applications until it starts to die back.


If you have a tree that you no longer want and want to kill it of completely rather than just chop it down and let it re-grow then you need to drill holes in the trunk and pour neat Glyphosate solution into these. As the plant takes down sugars it will also take down the spray. You may need to top up with solution form time to time. This is very effective against Eucalyptus trees.

How to order

You can pay online an your order will be dispatched to you, or come and collect it in person. Please see our shop page for prices (coming soon).