Long grass and rushes choke pasture growth every spring across New Zealand's lifestyle blocks and small farms, and a slasher mower or flail mower is the fastest way to bring a paddock back under control before seed-set. This guide from Implements Direct compares rotary blade slasher mowers with PTO flail mowers so you can match the right implement to your tractor, your paddock, and the amount of rushes you're actually dealing with in 2026.
- Del Morino Centurion 158 flail mower handles mixed grass and rushes on 25-45HP tractors at NZ$5,995 in 2026 — Buy.
- 36in galvanised slasher mower suits flat, grass-only paddocks on a lower budget — Consider.
- Sierra Verge Mower 1.45m reaches rushes along ditches and waterways with a hydraulic offset arm — Buy.
- Menasor 220 flail mower covers 8-20 hectare blocks fastest but is overkill on a single small paddock — Consider.
- Skip lightweight rotary slashers on thick rush tussocks; underweight decks bounce instead of cutting through.
Why this matters
Rushes spread fastest in wet, poorly drained corners of a paddock, and once they seed, they crowd out the grass species stock actually graze. Long grass left standing through late summer drops in feed value fast, turning into seed head instead of leaf. A slasher mower or flail mower knocks both back before they get away — but the two implement types cut very differently, and picking the wrong one wastes a whole afternoon.
A rotary blade slasher, like the 36in galvanised slasher mower sold through Implements Direct, uses a spinning steel blade to chop stems close to the blade tip. A PTO flail mower uses dozens of small hammer flails mounted on a horizontal rotor to shred material into mulch instead. On rushes — wet, fibrous, and growing in dense clumps — that difference in cutting action is the whole decision. Blades can bog down and wrap around thick clumps; flails mulch through and keep the rotor spinning.
Who this is for
This guide is written for lifestyle block owners running 2 to 20 hectares with rushes sitting in low-lying paddocks, small-scale sheep and beef farmers topping pasture ahead of a grazing rotation, and compact tractor owners in the 15-95HP range who need one implement to handle open grass paddocks and rush-choked ground along fence lines and waterways. If gorse or woody scrub is the actual problem rather than grass and rushes, the equipment list below changes — the section on what to avoid covers that.
What to look for in a slasher mower for long grass and rushes
Tractor horsepower match
Every slasher mower and flail mower on the market is rated to a specific HP band, and running outside it either stalls the PTO or strips gearbox life fast. Sub-compact models such as the Del Morino Ginger 1.25m suit tractors from 15-28HP, mid-size units like the Centurion 158 need 25-45HP, and the largest flail mowers in the Menasor range run on tractors up to 95HP. Match the model to your tractor's rated HP and rear lift capacity, not just the PTO shaft size.
Cutting width versus paddock access
Cutting width in this category runs from 1.25m sub-compact decks to 2.2m units built for bigger blocks. A wider deck covers ground faster, but only if your gates, culverts and headland turning space can actually fit it. Measure your tightest gate before ordering a mower wider than it — this is the single most common fitting mistake on lifestyle blocks.
Flail action versus rotary blade action
Flail mowers shred fibrous rush stems into fine litter that breaks down back into the paddock instead of leaving a windrow that can re-root in wet ground. Rotary blade slashers cut cleaner on dry grass but leave longer chopped sections on rushes, which regrow faster from the cut point than mulched material does. If rushes are your main problem, flail action wins outright.
Linkage category and PTO shaft size
Most slasher mowers and flail mowers built for tractors under 45HP use Category 1 three-point linkage. Confirm your tractor's pin size before ordering — Cat 1 and Cat 2 pins aren't interchangeable without an adaptor, and getting this wrong is a common reason implement orders get returned.
Offset reach for ditches and waterway margins
Rushes concentrate along wet ditches, drains and waterway margins where a straight rear-mounted mower can't reach square-on without driving through the ditch itself. A hydraulic offset arm swings the deck out beyond the tractor's wheel track, which is the difference between mowing a waterway margin properly every year and skipping it because it's awkward to reach.
Top picks for clearing long grass and rushes
Implements Direct's flail mower and slasher mower range covers tractors from 15HP to 95HP; here are the four picks worth cross-shopping for grass and rushes in 2026.
The traditional pick — 36in galvanised slasher mower
For flat, stone-free paddocks growing mostly grass rather than heavy rushes, a rotary blade slasher does the job at lower cost and simpler upkeep than a flail mower. The 36in galvanised slasher mower carries a galvanised deck that resists rust in the wet, rush-prone corners where this class of mower gets used hardest.
Verdict: Consider — solid for grass-only paddocks on flat ground; step up to a flail mower once rushes or light scrub creep in.
The all-rounder — Del Morino Centurion 158 flail mower
The Centurion 158 flail mulching mower cuts a 1.58m swath with 24 hammer flails and suits tractors from 25-45HP on Category 1 linkage. At NZ$5,995 in 2026, it mulches rush clumps into fine litter instead of leaving windrows that resprout, and it handles the odd blackberry cane along a fence line without stalling.
Verdict: Buy — the safest pick for anyone with a mix of grass, rushes and light scrub scattered through the same paddocks.
The ditch and waterway specialist — Sierra Verge Mower 1.45m
The Sierra Verge Mower for compact tractors runs a hydraulic offset arm with tilt adjustment, built for tractors in the 30-45HP range and priced at NZ$4,695 in 2026. It reaches beyond the tractor's wheel track, which matters because rushes concentrate along drains, races and waterway margins that a rear-mounted deck can't reach without driving through the ditch.
Verdict: Buy — the pick when rushes sit along drains and waterway margins rather than spread evenly across the paddock.
The wildcard — Menasor 220 flail mower for bigger blocks
For 8-20 hectare blocks carrying heavy grass and rush growth across several paddocks, the Menasor 220 flail mower's 2.2m deck and manual side shift cover ground faster than the compact models, at NZ$6,995 in 2026. It's built to mow under fence lines and around trees without repositioning the tractor for every pass.
Verdict: Consider — worth the step up if you're topping more than a couple of paddocks in one session; overkill for a single half-hectare block.
What to avoid
- Underweight rotary slashers on thick rush tussocks. Light decks bounce over dense clumps instead of cutting through them, leaving a ragged, half-mown paddock that needs a second pass anyway.
- Rotary blade slashers in wet ditch bottoms. Mud clogs the blade housing and stalls the PTO fast; a flail mower with an offset arm clears the same ground without driving into the mud.
- Gorse and woody scrub treated as a grass job. Standard flail mowers built for grass and rushes bog down on gorse over about finger thickness — see Implements Direct's guide on choosing a heavy-duty flail mower for gorse and scrub if that's what you're actually clearing.
Verdict comparison
| Pick | Cutting width | Tractor HP | Cutting action | Verdict |
|---|---|---|---|---|
| 36in galvanised slasher mower | 36in (0.9m) | Check current fitment | Rotary blade | Consider |
| Del Morino Centurion 158 | 1.58m | 25-45HP | Flail/hammer | Buy |
| Sierra Verge Mower 1.45m | 1.45m, offset | 30-45HP | Flail/hammer, hydraulic offset | Buy |
| Menasor 220 flail mower | 2.2m | Larger compact tractors | Flail/hammer | Consider |
FAQ
What's the difference between a slasher mower and a flail mower?
A slasher mower uses a spinning rotary blade to chop grass and light stems, while a flail mower uses dozens of small hammer flails on a horizontal rotor to shred material into mulch. Flail mowers handle rushes and light scrub cleaner because the flails don't jam on wet, fibrous stems the way a single rotary blade can.
Is a slasher mower good for cutting rushes?
A basic rotary blade slasher mower cuts rushes fine on dry, flat ground but struggles once rushes grow into thick, wet clumps. A PTO flail mower such as the Del Morino Centurion 158 handles dense rush clumps more reliably because its 24 hammer flails shred rather than chop the stems.
What horsepower tractor do I need for a slasher mower or flail mower?
Sub-compact flail mowers such as the Del Morino Ginger 1.25m suit tractors from 15HP, mid-size models like the Centurion 158 need 25-45HP, and larger units in the Menasor range run on tractors up to 95HP. Match the model to your tractor's rated HP and rear lift capacity before buying.
How much does a flail mower cost in NZ in 2026?
Flail mowers on the Implements Direct range in 2026 run from NZ$3,495 for a Hanmey 1.25m sub-compact model up to NZ$8,295 for the Del Morino Funny Super 106 hydraulic verge mower. Mid-range models built for 25-45HP tractors, like the Centurion 158, sit around NZ$5,995.
Can a slasher mower or flail mower cut through gorse and scrub?
Light flail mowers built for grass and rushes bog down on woody gorse and scrub over about finger thickness. Paddocks with established gorse need a heavier flail mower rated for scrub work rather than the standard grass and rushes models covered in this guide.
What cutting width should I choose for a lifestyle block?
A cutting width of 1.25m to 1.58m suits most lifestyle blocks under 10 hectares, matching sub-compact and compact tractors. Blocks over 10 hectares with several paddocks to top in one pass justify stepping up to a 1.8m-2.2m flail mower like the Menasor range.
Do I need a Cat 1 or Cat 2 linkage for a slasher mower?
Most slasher mowers and flail mowers built for compact tractors under 45HP use Category 1 three-point linkage. Confirm your tractor's linkage pin size before ordering, since Cat 1 and Cat 2 pins aren't interchangeable without an adaptor.
How do I stop a flail mower jamming in wet rushes?
Slow the tractor's forward speed rather than the PTO speed when working thick, wet rush clumps, and keep the flails running at full rotor speed for a clean shredding action. Raise the deck slightly on the first pass through tall rushes, then drop it for a second, lower pass.
One last thing
Rushes cut once in summer grow straight back from the same root clump — a single annual slash barely dents them. Two passes a year, one before seed head forms in early summer and one again in early autumn, knocks the root reserves down faster than mowing once and hoping. Implements Direct sees this pattern on lifestyle blocks every season: the paddocks that stay clear are the ones mown twice, not the ones mown with a bigger deck.