Flaggers on farmland

i think horses will eat them, a year of that should do the trick

Flaggers grow from a bulb. Therefore they have a strong root system. These bulbs multiply like spuds and daffodils. Cutting or grazing will not kill unless done numerous times durimg a year and leaf not left grow. Supprised Roundup did not at least stunt them. However they have a waxy leaf that may protect them. Using a activator that soften the wax and stick the spray will help. I imagine that really you need to like them now land is reseeded. Saw somewhere that MCPA and D50 works on them if so they are easly killed. I imagine that any scrub killer would hid them as well. They are also known as Fellistrim and technical name is Yellow Flag Iris. If you look up different sprays it should tell you which one treats them.

It may be a case of trail and error if you can get you hand on some of the above sprays and spray/lick different area's of them

Just came accross this
http://www.wcrc.govt.nz/Documents/Environmental%20Management/pestplants/Progressive%20-%20Yellow%20Flag%20Iris.pdf

In the spring time when the flagger is around 18 inches tall, I spray with MCPA (at the high rate per hectare) with a wetting agent as mentioned.

4-6 weeks later, the aerial/exposed part is "sealed off" with a plug at the base of the green part - like what you get in the autumn die-off with normal growing conditions. That year they will eventually die off.
I repeat this every year: really I'm just controlling the spread of them, it does reduce the density of the flagger clumps along with topping also.
I've lost some clover because of the MCPA but at least it's not like roundup which hammers a job on everthing green.

Digging up this old thread as still struggling with Flaggers here.

What is the best spray nowadays for them - it is still D50 or MCPA or will the likes of the newer sprays like Forefront T kill them ?

Has anyone on here managed to successfully kill them and they haven't come back ?

Thanks.

This is them the feckers

Flag Iris. A sure sign of wet ground. They're recognised as an important part of our native biodiversity and great for pollenators.

https://teagasc.ie/environment/biodiversity--countryside/growing-wild/yellow-flag-iris-php/#:~:text=Look%20out%20for%20yellow%20flag,three%20narrow%20smaller%20upward%2Dpointing%20petals.

It is one of the positive flowers in ACRES, increasing scores and payments. 

Lick them with glyphosate and a organosilicone penetrant

Just thinking would Round-Up in a weedlicker be a good option for these 'Flaggers' ?

Has anyone tried it and had success ?

Hello Sami23… i feel your pain. I have a 5AC field full of them. There are a lot of theories on how to kill them, but they are very very tough. One man tole me all i have to do is spray with D50 & a sticker… he said it worked great to erradicate his. When i tried this, they did wilt away after a couple of weeks but were back the following year just as bad. Licking with roundup just stunts them but does not kill them. These creatures are like the teminator. Refuse to die. Just look at their roots? Its like a carrot. Have you tried anything yet? Surly in 2026 there must be some way of handling these feckers?

Yes it would be interesting to top them very regular for a year and starve them of nutrients. (I understand you cannot do this)
Ive also heard that MCPA works well on them… so id be very interested to hear how you get on after that spray you did last Friday

Did you add any sticking agent to the MCPA? Even washing up liquid is used just to hold it on to penetrate

I was spraying briars last month with Grazon90 in a knapsack… i had a little left over and tried it on a bunch of Flaggers

They have since withered away.. will keep an eye on them to see if they return!
Looking forward to hearing how you get on with the MCPA

Did you have any success after spraying the flaggers with MCPA?

Good to hear they are looking poorly… but they normally bounce back the following year. Yes please do post a picture and lets see if they die off for you. Even a 50% reduction would be fantastic