Mulch Mowing

A big question mark remains over the merits of this type of grass cutting. Les Malin from Etesia UK – a brand synonymous with the DuoCut system – cut, collect or mulch, takes a closer look at the pros and cons.

Mulch mowing saw a resurgence of interest when we enjoyed a few dry summers in a row in the late ‘1990s. Despite more companies now offering mowers that can mulch, acceptance of mulching remains low. There are a whole host of reasons why, ranging from mowing frequencies to dealing with long wet grass. So should we just accept it is of limited value in the UK?

Anyone who has looked at the way rotary mowing has evolved over the past five years will be struck by the increased availability of what can broadly be termed mulch mowers.

On the pedestrian mower front, the term should really be broadened to suggest more manufacturers are offering mowers that can mulch. Dedicated mulchers are now sold alongside 3-in-1 units that can also bag clippings.

Sward Absorption
It is this trend to multi-role machines that perhaps answers the whole issue surrounding mulching. There is nothing wrong with the idea of chopping grass clippings so small that they are readily absorbed into the sward. Gang cylinder mowers have proven this approach works well.

Where rotary mulch mowers have perhaps been at a disadvantage is in the way in which they are expected to operate. Instead of being used like a gang in little-and-often mowing, they are used like a conventional rotary, and expected to reduce grass of 6 or more inches to perhaps an inch in a single pass.

A rotary mulcher works by both re-chopping the grass to produce small clippings and to then blow these down into the sward.

The aim is to leave the resultant finish free of surface clippings. This can only be achieved when the sward to clipping ratio is correct.

Mush and Mud
Add excess moisture, and accumulated mush of wet grass and mud that can result has led many to believe that mulching just does not work.

It is perhaps worth taking a side step when looking at mulching and to consider the whole technique as an ally, as opposed to an alternative, to conventional rotary mowing.
Rotary mowers, particularly for ride-on commercial machines, have evolved from units designed essentially to ‘knock’ grass down, to machines capable of producing a good finish. Remove the resultant clippings, and there are those who argue commercial cylinder mowers have no real advantage in terms of actual finish.

It is this quality of cut issue that has taken the emphasis away from mulching. In terms of appearance, grass regularly mown with a good rear discharge rotary will give little away, in terms of appearance, to that cut with a cylinder gang.

The aim is to allow users to mulch and so reduce the amount of clippings left on the surface when conditions allow. This enhances the appearance of the turf post mowing but without compromising wet weather cutting ability.

This brings us back to 3-in-1 pedestrian mowers. With a ‘bung’ or similar device closing off the mowers outlet, the clippings are mulched. Take out the bung and the clippings can either be discharged to the ground or a bag. Versatility is again the key.

Many feel this is the approach needed to allow some form of mulching to gain a firmer foothold.

There are those, however, who are already strong advocates of mulching, and they suggest we all need to rethink how mowing is carried out, particularly where grass is collected.
In a typical wet spring and early summer, grass growth will typically outstrip any mowing regime’s ability to keep it trimmed effectively to summer heights.

Evaporation Help
But, as the season progresses, warmer conditions allow faster evaporation and with it the chance that grass can be mown when it is dry or at least moist.

Shorter grass also loses water faster so wet mowing can be avoided more easily.
A side effect, however, is the well-understood result that relatively high levels of summer rain are required to keep and sward lush and green.

Come late June (apart from this year!) and many areas will see non-irrigated turf starting to dry or even brown. It is here where a switch in early June from conventional cut and collect mowing to mulching can have a place.

The returned clippings will help retain moisture and also return nutrients to the sward. As long as the regime allows the sward to be maintained to a moisture loss resistant inch or so, this and regular mulch mowing can help keep the grass greener for longer.

There is also the issue of not needing to remove clippings. Clipping disposal is a hot topic at present, so it may be that mulch mowing starts to become recognised as an alternative in regimes that currently call for cut and collect mowing. The secret is to keep an open mind and give mulch mowing a chance.