Three cornered leek....arrrgh

Hello everyone. I have a question about the dreaded three cornered leek.
Now, I have inherited a previously neglected garden which is rife with the stuff.
I know the ultimate removal method is to dig them up which is what I've been doing in the beds but I have a lawned area that is rife with the stuff.
So I would like to ask if anyone has any experience with using Dicophar 4 way selective on a lawn ?
AI has said that it is ok to use on grass but I won't trust it's answer on whether it would be effective on three cornered leek.
Any thoughts anyone ?

 

Google AI also informs that Dicophar is fine to use on lawns, but will not get rid of 3 cornered leek.
It recommends Glyphosate applied as a gel to the individual plants - I have a recipe to make gel if that will help.
It will likely take several applications of Glyphosate as the bulbs underground and any seeds won't be affected until they shoot above the soil surface and can be treated with Glyphosate.
Repeated mowing will kill them off eventually, but that will take several seasons.

AI Overview
Dicophar 4, a selective weed killer for lawns and amenity turf, is
not generally recommended or effective as a standalone solution for eradicating three-cornered leek (Allium triquetrum). The most successful methods involve a combination of manual removal and a systemic herbicide like glyphosate.

Effectiveness of Dicophar 4
Dicophar contains four active ingredients (2,4-D, Dicamba, Mecoprop-P, and MCPA) and is primarily designed to control tough broad-leaved weeds like yarrow and buttercup in grassed areas.

• Limited Efficacy: While some selective agents have shown success with related species, Dicophar's active ingredients are unlikely to provide complete eradication of the resilient bulbs and seeds of the three-cornered leek.
• Persistence: Three-cornered leek is an invasive species with persistent bulbs and a vast seed bank, requiring a potent, systemic solution that Dicophar does not offer.

Recommended Control Methods
The most effective approach combines manual and chemical controls, applied persistently over time.

Manual/Cultural Control

• Digging: For small infestations, digging up the entire plant, including all bulbs and tiny bulblets, is recommended. This is best done in spring before flowering.
• Prevent Seeding: The plant spreads aggressively via seeds, often carried by ants, so removing all flower heads before they mature is crucial.
• Repeated Cutting: Consistently cutting the foliage at ground level can eventually exhaust the bulbs' energy reserves, though this can take a long time.
• Proper Disposal: Do not compost the plant waste, as the bulbs and seeds can survive and spread. Dispose of it as "hazardous" plant waste or burn it.

Chemical Control (Recommended)

• Glyphosate: A systemic weedkiller containing glyphosate is generally considered the most effective chemical option.
  • Application: Bruise or lightly trample the leaves first to break the waxy surface and improve absorption. Carefully apply the chemical directly to the plant foliage.
  • Timing: Apply in spring before flowering for the best results.
  • Caution: Glyphosate is non-selective and will kill other plants it touches, so caution is needed, especially in garden beds.

Due to the plant's highly invasive nature and the legal ramifications of allowing it to spread in the wild in the UK, professional help may be necessary for large or stubborn infestations.

 

Hello Pete, thanks for your reply. Your recipe for a gel is a good idea. I have a bottle of Glyphosate and would appreciate the recipe. Hopefully between that and mowing I might be able to get a grip on it.
Many thanks.
Colin.

 

Hi Colin
Glyphosate is very good, but it only works when weeds are actively growing, so only use between around March/April and late Sept. At other times of the year it's unlikely to have any effect.
It is only absorbed by leaves and not any other part of the plant.
It has no effect on soil or roots.

To make a gel, I get a small pack of wallpaper paste (98g).
If you're using ready-to-use Roundup, pour some into a jar and add 1/2 to 1 tsp wallpaper paste, stir and see how thick it gets after about 5 mins.
The leaves are waxy, so bruising them first may help absorption, then using a small brush carefully paint the leaves.

I use the concentrated form of strong glyphosate (Glyphosate 360).
The dilution rate is 15ml Glyphosate 360 to about 500ml water.
Add a teaspoon of wallpaper paste and stir - you may need to add more if it's not thick enough.

It'll be at least a week before you see any difference, but after a couple of weeks you should see the plant is dying.

I've found that after about 1 day the mixture becomes very thin and watery, so only mix what you'll use or re-thicken it with more paste.

There's a bit of trial and error, but I'm sure you get the idea, just use the wallpaper paste to thicken the mix so it coats the leaves and doesn't just run off.

Good luck!

 

Thanks for that Pete.
I'll give it a go next spring

All the best.

 

Dicophar is not approved or available legally for amateur use in GB &NI.

Plant is edible and sought by foragers.
Unlawful to place or maintain in open countryside as it is a non indigenous species.

 

If it's in the lawn, just mow it. It is green after all. Weedkillers are noxious to wildlife as well as plants and a real problem as they leach into waterways.

I have it appearing in a couple of my hosta pots where it does its thing before the hostas really get going and then get hidden. It's also popped up in some gravel and there we hoe it. Any in the grass gets mowed unless it's in the bits we leave unmown for the wildflowers.

If it pops up in beds where I don't want it I either take it out with a trowel if that doesn't disturb treasures or else just cut the leaves to the base so the bulbs starve.