Koro vs Total Weed Control is a blog on the regeneration of grass species with the removal of weed grasses with the option of also the removal of organic material (thatch). This blogs explores both options as some squares aren’t suitable for Koro or Fraise mowing, for a few factors.
Koro/Fraise Mowing-Planing
Koro -readdress levels – completely removal of the top grass sward including offending material such as thatch/roobreaks, saddles (high ends) whereas fraise mowing/planing is a shallower form just removing shallow rooted weed grasses, leaving more desired species to grow back.
Pro/Cons
C-Expensive in comparison to total weed control
C-Removal (Koro only) of existing soil /old loam layers for the sake of it is the removal of a vital material /resources ie loam
C-Wash off risk, little or no existing grass and a smooth clean surface will heighten seed wash off risk.
C-If the square is lower than the outfield, by removing more soil via koro (surface planning) you could make the problem worst., this could be factored in those with a higher volume of loam application, if feasible for clubs.
P-Lots of organic materials removed
P- Fraise more a lighter form of koro work just working at removing a minimal amount of soil, with shallow rooted grasses being the main target.
P- Leaves a clean job, clean of all organic material which if left could have a detrimental effect on pitch performance.
Total Weed Control
Pro/Cons
C-Unless you have a spraying licence you’ll need to pay some certification to do so.
C-Chemical used will kill off the all-grass cover, if on public land this could raise concern to other site users.
C-Can be challenging to ensure a complete even spray off, if contractors do not use a in tank dye
C-A certain amount of dead plant material will be left on the square after scarification, this should die away but also a small amount could end up back within the soil as organic material which is not ideal, compared to a clean koro off. The leaf should disintegrate away, but the stem is formed or a material called lignin, and l have been told this doesn’t rot down so well, so to my question below..
Question-Is that a shared view point or am l wrong in my thinking?
C-Environmental concerns using toxic materials on public pitch or sites with shared users and to you as the user.
P-Total weed control is a cheaper option on the face of it than koro work, but it doesn’t give you the full list of options the koro does listed above. But if funds are limited and the squares needs regeneration of grass species over the old weed grasses this can be something to at least explore with the guidance of your peers.
P-Doesn’t remove any soil or organic material but it will kill off ALL existing grass cover including unwanted weed grasses (POA), then the aim is to scarify as much as the dead grass as possible. These scarification lines can then be used to seed and top-dress into as required.
Summary
If thatch or and root breaks in top of soil profile and suitable for your situation then maybe best option – koro
If just weed grass removal total weed control could be the option (if organic material is not a concern as in above questions), as well as exploring fraise mowing.
Starting Point
The starting point comes with accessing what you need via exploration of the top of the soil profile to gauge and look at the make-up of the square including exploring surface levels with the help of a peer or pitch advisor and/or a reputable experienced sports turf contractor.
As a working Groundsperson, l am just a bit stuck on going forth with total weed control, as l am concerned with the possible dead material l don’t remove and if that could in turn affect pitch performance going forward or forward its demise. Once that’s answered in my own head, as a certificated person l d probably consider it as a real option!
The aim of this blog is to open up the conversation and bring about some clarity as there is an increase of squares being sprayed off now pre renovations and l d like to explore if this a option l can add to my own tool box !
Please do leave comments below for the benefit of all readers to view, its a subject l know could bring about a wide range of opinions.
Brian
For a insightful blog comparing Koro vs Fraise mowing take a look at this blog – https://turfcareblog.com/koro-field-top-maker-vs-fraise-mowing/
4 comments
lets have your views, this blog is to open the conversation and explore and learn from for me and those reading in interest.
Koro very expensive but very good.
If budget not available an awful lot of good can be achieved by spraying of all grass.
Then verti cut in several directions followed up by mowing with the pitch mower set to almost soil level, in several directions.
Finally scarify, overseed and top dress as usual.
Very time consuming but a much cheaper option.
Concerns regarding stem breaking down creating excessive dead material build up in the soil profile
G Gill
I have done both ways in the past and indeed a combination of the two. I used to do seed trials so I needed to kill all grass off. I have the means to Fraise Mow.
When I started spraying off prior to having fraise mow capability getting rid of the dead vegetation was an issue and mustn’t be overlooked or only partly completed. What I did when I didn’t have fraise mow capability was to scalp and I mean scalp on occasions the cylinder mower “bottoming” I then scarified and scarified till the surface was almost “Fraise Mown”. Then scarified or veri seeded if damp enough and sowed at about 80gms/m (and I didn’t have wash off problems) followed by top dressing with the normal amount of loam.
I believe that there are now ways of “Fraise Mowing” much more readily available and not as expensive as using a large tractor with a soil planing machine and a separate unit to collect the arising. There is a popular tractor mounted scarifying machine which has a fraise mowing reel and a collection box. Also available is a pedestrian machine with fraise mowing reel again with a collection box. These two are much less expensive than the big tractor with Planing machine, make the job more available to smaller clubs who can really benefit from the process.
I know that Headingley was Fraise Mown with a pedestrian machine at the end of the 2023 season. To me rewards are worth the effort and cost which may not be as much as you may think as long as you leave yourself enough time for the grass to germane and establish before the cold weather sets in.
David Hodgson
Hodgy
Brilliant information and insight and organic material was concern so good to help how to remove via scalping after spray off Ie once the plant is dead . Thanks for taking the time to comment.