Mains, battery or petrol
Corded electric is where most gardens land. No fuel or oil, effectively nothing to service, and far less noise than a petrol engine. The cable is a genuine nuisance on a large or awkwardly shaped plot and a tolerable compromise on a small one — and since a scarifier comes out of the shed perhaps twice a year, that compromise costs less than it sounds.
Battery machines remove the cable and pay for it in power. They only scratch the surface: a deep setting of -10 to -15 mm is beyond them, emphatically so in heavy, densely rooted ground. Runtimes are short, none of the cordless machines here gets past about 34 cm of working width, and none carries more closely spaced blades to compensate; they also have noticeably fewer claws on their aerator rollers. Cordless makes sense mainly if you already own the right batteries, and on a plot broken up by corners and curves.
Petrol comes into its own beyond roughly 1,000 m², and more precisely where that area is broken up by buildings and shrubs and there are too few outdoor sockets to work round. Against it: oil changes, refuelling, and an engine that may not start. These are four-strokes running on ordinary unleaded — no expensive manufacturer-branded grade is needed — taking the engine-oil grade the maker specifies, with the level checked periodically and wearing parts such as plugs, carburettor and exhaust to come.
The picks
Top pick — Husqvarna S 138C
The best choice for small to medium gardens where a cable will reach everywhere. Among the corded electrics it was the most convincing machine in the test, with build quality and ease of use both above the level of the competition. It is not the machine for a garden over 800 m².
Power draw is a moderate 1,050 to 1,130 W, but a lot of it arrives at the ground. On the sandy soil of the test lawn it had no general difficulty; where it stuck, the cause was thick grass tussocks rather than too deep a setting. Tracking is straight and keeps ground contact despite the low weight — not every small clod of turf sets it hopping. The roller turns at 6,000 rpm from 1.6 kW.
The body is a hard, unyielding plastic that cannot be flexed or pushed in at any point. The handlebar follows much the same principle as the rest of the field but to a better standard — greater weight, larger diameter, better wing screws — and the difference is obvious at a glance. It cannot match a steel-sheet or polymer construction, but it is a clear grade above the simple polypropylene machines. Rubber-tyred wheels look built to last, the quick-release nuts cannot fall out once loosened, and the Bowden cables are protected where the handle folds.
It arrives fully assembled, and folding it away needs only two quick-release catches. The 45-litre collection box is the weak point: seating it is fiddly and takes longer than it should. That mattered less than expected, because on this lawn collection boxes filled far too quickly whatever machine they were on — largely with the stones and sand that ought to stay put — so gathering the moss and thatch afterwards with an iron rake was the better answer.
Two real drawbacks. The blades score to 8 mm, and depth is set by a rotary knob fixing the end position of the linkage and therefore the roller — but the knob carries no markings, not so much as a reference point, so there is no way to note which setting you are on. A lever would also let you lift the roller to cross a path without stopping; with a knob that is not possible and changing over takes longer. And the aerator roller is fixed with a hex socket, a step behind the models that swap without tools.
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The cordless one that works — Stihl RLA 240
The first battery machine here that convinces, and only for small lawns on soil the blades can get into. It suits a tended, smooth lawn rather than a woodland meadow, and it is a sensible buy chiefly for someone who already owns the right batteries.
Two 2.4 Ah packs went into the test. A charge gave a good half-hour of continuous running; on the middle setting it ran 31 minutes with roughly 25 stops to empty the box, which does not cover much ground, so a second battery is essential. A deep setting should be reserved for soft, permeable ground with few obstacles such as stones, wood or pine cones, because otherwise the motor bogs down and cuts out — the same happens over small unevennesses, where the blades suddenly meet deeper soil.
Build quality is solid without reaching the maker's semi-professional machines: rubberised wheels stably mounted, wing screws that cannot fall out, and the simple polypropylene chassis used across this class. The stepless depth adjustment is less practical than it sounds, because you have to read the groove you just cut to judge the depth, with no scale to remember a setting by. A well-balanced carrying handle makes it easy to lift at 14 kg without the battery, and handle height changes quickly to any position with a clamp screw.
The aerator roller is supplied and stows cleverly inside the machine beside the fitted blade roller; swapping needs the supplied hex key because the bearing is bolted, and that plastic bearing is a wear part, so a spare is included. Folded, the machine fits the smallest boot. Two irritations: the box will not come out through the handle despite an otherwise exemplary fixing, so it has to be taken from the rear and refitted from above, and there is a gap between box and flap through which sand is thrown back towards the operator.
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Leaves the sand where it belongs — Bosch UniversalVerticut 1100
A corded machine built around a genuine idea: it takes out what should actually leave a lawn — moss and thatch — and leaves the stones and sand behind. Where other scarifiers drive fixed blades through the ground at speed and fill the box with sand, this one fills the bag with moss.
The mechanism is a large plastic roller pierced with air openings, generating an airflow that carries the lifted moss and thatch into the box. Stones are too heavy for that airflow, or never get torn out at all, because the steel blades sit at the rim of the roller on loose bolts and fold away when they meet an obstacle — only the speed of rotation stands them up to bite into the sward. Hard obstacles such as a paving slab or a field stone get scratched rather than smashed, which makes for smoother going, without the violent knocking and loud clattering of flung stones other machines produce.
The drawback can be decisive: for a deep cut at maximum depth, 1,100 W is not enough, or the folding-blade principle is not ideally suited to it. On ground with firm patches and thick tufts of grass it cut out regularly, and the slightly shallower setting had to be used instead — which worked well and left neat, even grooves.
Storage is very good. It folds flat and the stackable box comes apart and nests inside itself, so the whole thing takes very little room. The handle varies by 3 cm in length at assembly, which helps taller users, and the box drops into its catch beautifully. Against that, the box's click mechanism does not look durable, the same suspicion attaches to the red wing screws, and like most machines here it is plain polypropylene, with a body less stable than the top pick's.
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For very large lawns — Hecht 5676
A petrol heavyweight, which is exactly what makes it right for driving evenly through a big area — beyond about 800 m², where a cable is out of the question. The steel-sheet chassis gives a settled, smooth run that the strong four-stroke makes essential. It weighs 37.6 kg and measures 103 dB(A), which the neighbour but one will not miss.
The robust roller scores as deep as 15 mm and the drive is not stopped by firm clay. The engine has two to nearly three times the power of the electric machines here at 1,200 to 1,400 W: the 5.8 hp four-stroke spins the roller at 3,600 rpm. The electrics reach that and usually exceed it — the top pick runs at 6,000 rpm — but only from 1.6 kW, and it is power rather than speed that allows deeper scoring in heavy soils and dense swards. Working depth is set centrally in six steps, with 15 sturdy blades across a 40 cm width.
Handling is thought through. The engine does not have to be stopped to change the box: a pull lever on the handle lifts the roller into a park position, which is also how you cross a path. The supplied aerator roller changes with a hex key, a low-oil sensor guards against engine damage, and the 0.8-litre tank gives 45 minutes to about an hour depending on revs. There is no wheel drive and none is needed, because the tines pull the machine forward as they bite. It is also very large: the handle folds, but what remains is a bulky, hard-to-shift colossus that needs somewhere to live, and the oil changes are a standing commitment.
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Cordless for a well-kept lawn — Einhell GE-SA 36/35
Suited to medium areas up to 600 m², and only ones the blades can get into: sandy soils with light to medium moss. On the partly heavily thatched test lawn it would run only at step -3 of -6/-9, because the motor will not manage deeper; on the well-drained sandy patches step -6 was possible, but too much moss stalled it.
It earns its place on what cordless buys. Freedom of movement makes for faster, more pleasant work, particularly if you run without the box and rake afterwards, and the trade is a clearly reduced power output. With 15 blades on the roller and a measured working width of 33 cm — the maker quotes 35 cm — it needs a few more passes, and more width is simply not available on battery drive. At 94 dB it is one of the quietest machines in the test, and it will run 30 minutes, though only in the first depth setting.
Housing quality is basic with some good details: reinforced wheels, and hand clamps in tough GF30 plastic with washers behind them. Set against that is a plain polypropylene chassis with no reinforcement against stone strike, a thin battery cover, and a handle catch that wears heavily from folding. The 28-litre box is far too small and sits on a thin metal frame that bends easily. This is a basic housing not built for frequent use, and the lower fixing is best left as it is when parked, because folding it the wrong way once breaks the plastic webs. It is a poor answer for heavily mossed ground and for heavy clay.
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Also tested
Wolf-Garten VA 346 E — the one for covering ground if you prefer a cable to petrol. A strong 1,600 W motor never bogs down even at the deepest setting, at the cost of being a shade louder, and the 34 cm width gives good coverage; a 37 cm version exists. Central roller adjustment by lever and Bowden cable lifts and drops the blades, which nothing else at this level offers and which saves lifting the front axle to turn or cross a hose. At 15 kg it is light — good for carrying, less good for tracking — and folds to 42 cm by 72 cm. The aerator roller swaps without tools. Users beyond 1.85 m will struggle; maximum height was just adequate for a 1.82 m tester. Box removal is excellent, though the plastic lug holding the box hoop does not look durable. Search Amazon UK · Search Amazon US
Stihl RLE 240 — quieter than the rest and, thanks to 16 kg, a steadier run. Build is better than most entry-class machines: solid box lugs, a box that latches reliably without looking, rubber-treaded wheels almost nothing this cheap offers, and a rigid handle whose wing screws cannot fall out when it folds. Working width is only 34 cm, so a few extra passes are needed — which hardly matters when six closely spaced blade pairs cutting at 1.5 cm intervals, against the usual 2.5 cm, fill the box so fast. Depth is stepless to 15 mm, which proved ample; deep cuts to 25 mm are mostly a petrol trait. A spring-tine roller is standard, changed by two hex screws rather than a quick release. Folded it is 71 cm by 56 cm. Search Amazon UK · Search Amazon US
Stihl RL 540 — the petrol machine for areas beyond 1,000 m². Its 150 cm³ engine has no trouble in the thickest moss, where electrics sometimes stick. The body is UV-stable polymer, a heavy hard-plastic chassis reinforced with metal struts; the four-stroke contributes a good share of the 33 kg but the body accounts for plenty too. It is more manoeuvrable than that weight suggests. The thick rubber inside the rear flap flexes when it drags and damps the stone strikes the roller does fling at it. A lever adjusts blade height and working depth while the engine runs. Against it: bulk, noise, four-stroke servicing, and a storage footprint of 84 cm by 65 cm, markedly larger than the rest. Search Amazon UK · Search Amazon US
Gardena EVC 1000 — a mini scarifier for small areas and easy ground. A modest 1,000 W drives a narrow 30 cm width, but it works that width thoroughly on a blade spacing of only 1.5 cm and pulls out a lot of debris. A box is optional, so the debris normally stays on the lawn. There is no handle height adjustment — the handle is loosely mounted in the plastic chassis, and metal wobbling in a plastic guide does not look durable. With no box fitted, larger stones can be flung at the flap, so the maker made it from a soft, impact-resistant polypropylene. At 9 kg it is agile around shrubs, though the tiny rear wheels sink into loose sand and carry the load in turns. Depth is set in three steps; the manual does not say how deep, and measurement put it at 10 mm. Search Amazon UK · Search Amazon US
Makita DUV320Z — a cordless machine of usable quality with only 13 minutes of running time, and that needs the 6 Ah battery. Assembly is fiddly, and the roller runs on a plastic axle, but the box clicks easily into its lugs and depth adjusts centrally. On the lawn it disappoints: too light, so small undulations, wood or stones set it hopping, and the scoring comes out uneven. An aerator roller is included, released with a hex key. Search Amazon UK · Search Amazon US
Makita UV3200 — reasonably solid, with practical quick-release catches instead of wing screws, rubberised wheels and a variable-height grip. The ergonomic downsides are tiny rear wheels and a deep front skirt that keeps touching the ground on turns or over grass tussocks, costing both feel and tracking, plus a plastic bridge between the wheels that snags and serves no purpose. No aerator roller is supplied. Search Amazon UK · Search Amazon US
Worx WG855E.9 — a light cordless machine, 36 cm wide, whose four-step adjustment takes the blades to 9 mm. That is less than the corded machines manage but enough on accessible, level ground. In a middle step it ran 15 minutes on two 2.0 Ah packs, covering around 300 m². At 94 dB(A) it is clearly quieter than a typical corded machine. A small 40-litre fabric box and an aerator roller are included, the roller swapping without tools. Construction is the problem: thin plastic wheels, a wobbly handle and an unreinforced polypropylene flap. Motor stopping is prompt. Search Amazon UK · Search Amazon US
Einhell GC-SC 36/31 — a cheap cordless model of inferior quality and no box. With a shallow 12 mm reach and just 12 minutes on two 3.0 Ah packs, results are acceptable only on small, accessible areas. It is the little sister of the recommended GE-SA 36/35 on the same 18 V batteries, and the bigger machine stays preferable because its heavier chassis rolls more steadily and the box is included rather than extra. Noise is low. During testing the unreinforced polypropylene flap was torn off its mountings by stones when a hinge pin gave way. Search Amazon UK · Search Amazon US
Einhell GE-SA 1640 — mid-range, comparatively stable, with good ergonomics: the grip tilts and extends by 5 cm, and has a real rubber cover rather than the sprayed-on finish used elsewhere. An aerator roller and a large, flexible 48-litre box are in the carton. The almost imposing 40 cm working width is why it is so bulky — 57 cm across, wider than anything else here — though 12.8 kg is not heavy. Search Amazon UK · Search Amazon US
Einhell GC-SA 1231/1 — weak build, too small a box, a bouncy ride. The 1,200 W does dig through the grass, but the machine is far too light and keeps pushing itself up, so even grooves never happen. Height is set separately at each front wheel. Compact storage is the one plus. Search Amazon UK · Search Amazon US
Einhell RG-SA 1433 — compact and light with a strong motor, and the lightness is the whole problem: the roller bites so hard that it repeatedly lifts the chassis and the wheels lose contact, so getting an evenly deep cut out of 1,400 W takes patience and still comes out uneven. Depth is set at each front wheel, with two working steps and a park position. The rattly plastic frame has no metal reinforcement, the polypropylene flap is unprotected against stone strike, and the tiny box fills far too quickly to be worth using. In its favour, the motor does not stall, the wheels are half decent, handle height adjusts, and the supplied wire-claw aerator roller suits the low weight and works better than the blades do. Search Amazon UK · Search Amazon US
Einhell GC-ES 1231 — another cheap entry model with no aerator roller and no box, and comparatively stable construction for what it is. Decently made within the limits of polypropylene, but it throws up a great deal of sand and grit — far more than necessary, as the air-collection machine demonstrates. Search Amazon UK · Search Amazon US
Hecht 1999 — moderate quality in a far too light housing. Small obstacles such as wood or fir cones lift the chassis and stop the scoring being even, so a strong 1,280 to 1,350 W never reaches the soil consistently. The low weight also lets a full box tip it over backwards, though the box comes off quickly. Depth adjustment is central and simple, but the knob gives no indication of where the blades are. An aerator roller is supplied and needs tools to fit. Search Amazon UK · Search Amazon US
Parkside PLV 1800 A1 — the 2024 model, up from 1,500 W to 1,800 W, with build quality that has gone the other way. The all-plastic chassis and rear flap will not stand frequent use, and the viewing window in that flap invites stones to smash it. The box is a wobbly construction of thin fabric on fragile steel rods. The thin handles hold the running gear passably on line and the fairly large wheels roll well, but at 9 kg the machine is too light and dense root mats keep lifting it. With a working width of only 36.5 cm and 20 blades it suits very small areas only. It folds neatly to 58 cm long and 41 cm high. Noise is a comparatively high 98 dB. Search Amazon UK · Search Amazon US
Brast BRE-RV-3800 — a decent 37 cm working width carrying 20 blades, relatively many for the width, and an optional aerator roller with only 20 claws. The build, and above all the chaotic folding mechanism, disappointed: release the catch and the handle has nowhere to go, leaving an untidy heap, though the fabric box will lie flat over it. The polypropylene body has no reinforcement against stone strike, the plastic wheels do not look durable, and the box hangs on plastic lugs that could break despite its metal frame. On uneven ground the too-light machine with its swinging handle is hard to hold on line and sometimes has to be pressed down to stop it lifting out, especially on heavy soil. The deep front skirt can block progress over undulations. Search Amazon UK · Search Amazon US
Stiga SV 415 E — small and compact, only 32 cm wide but carrying 19 blades, which gives a tight slot pattern. Instead of a deep front skirt it has a shallow rising ramp, so the grass slips underneath and the blades need lifting out less often. Height is stepless. The moderately loud motor and the aerator roller with 40 claws — a great many across 32 cm — are both likeable, and whichever roller is not in use stows in the machine. Overall quality is middling at best: an unconvincing push-together plastic box on plastic lugs, plastic wheels, a body unreinforced against stone strike, and knurled screws that can fall out. It folds tidily, after which the non-folding box is almost bigger than the machine. Search Amazon UK · Search Amazon US
Hyundai SC3601E — a mixed impression. Chassis, quick-release catches, wheels and rollers all look simply made, the sheet-metal claws could deform with prolonged use, and the box works loose while pushing even when empty. The motor has a high, noticeable tone. On the plus side there is a wall bracket for storage, a tool-free aerator-claw change and straightforward depth adjustment. In use it lost traction in dense sward and produced a strong smell of smoke, and the work rate fell well short. Search Amazon UK · Search Amazon US
AL-KO Combi Care 38E Comfort — for small gardens, generously equipped with a large fabric bag and an aerator roller where others charge extra for both. The bag proved fairly pointless because it filled with sand and moss almost immediately. Quality is no milestone: thin wheels, a weak handle assembly, an unpadded rear flap. It is inexpensive, stores compactly and does its job, with enough motor for small to at most medium areas up to 600 m² — two to six outings a year rather than continuous use. Search Amazon UK · Search Amazon US
AL-KO Combi Care 38P Comfort — the same chassis as the electric version but carrying a heavy petrol engine, and it shows. The handle assembly is too weak and twists constantly while manoeuvring, and its anchorages needed to be stronger here than on the electric model; the likely outcome is the plastic going brittle and the handle eventually breaking out. A shame, because the engine is stronger than the electric version's and works through difficult ground, starting easily, if rattling louder than the top pick. Search Amazon UK · Search Amazon US
AL-KO Combi Care 36.9 E — comparatively quiet, and supplied with an additional aerator roller. The box mounting looks low-grade, and the plastic wheels, wobbly handle and feeble lid do not look durable either. Search Amazon UK · Search Amazon US
AL-KO SF 4036 — a step into cordless. The 36 V / 5 Ah version managed 15 minutes at step 2, enough for a small garden, with central stepless height adjustment and usable build quality. But it sticks regularly at the deeper steps 3 to 5 and the motor cuts out, and across a generous 36 cm working width it carries only 12 individual blades where most machines at 32 or 34 cm carry 18 — fewer claws precisely because more would leave it stuck. Search Amazon UK · Search Amazon US
Wolf-Garten VA 303 E — close to the AL-KO Combi Care 38E in quality, size and output, and a cheap entry machine for small areas up to 600 m². The motor sticks in thick moss, as the AL-KO's does. An aerator roller is included and comes off and on without tools. Two things count against it next to the AL-KO: 30 cm of working width instead of 38, and a smaller 35-litre box. Search Amazon UK · Search Amazon US
Ikra IEVL 1840 — cheap, in plain plastic, and poorly or indifferently finished in many places: unreinforced plastic wheels, simple wheel mountings, an unstable lid with no protection against stone strike, a wobbly handle. The supplied aerator roller does not make up for it. It does park small, at 54 cm high and 71 cm long. Search Amazon UK · Search Amazon US
Scheppach SC38 — makes fewer design mistakes than its SC32 sister, but calling the frame and chassis stable would be a stretch. The plastic wheels are unimpressive, folding is fiddly and the machine is too light overall, so it hops over tussocks and bits of branch and loses the line. An aerator roller is included. The box hangs on plastic lugs that could break. The loud, bright whine of the motor is bearable rather than pleasant. Search Amazon UK · Search Amazon US
Scheppach SC32 — good for nothing beyond a pocket handkerchief of a lawn. The fiddly folding arrangement, the cheap wheels with a mounting that borders on a joke, and the hopping progress convince nobody who has handled a decent tool. It is too light to hold a line and too rattly to be a lasting investment. Search Amazon UK · Search Amazon US
Onbest 2-in-1 — a cheaply made budget machine with central height adjustment, an aerator roller and a fabric bag, the roller changed with the supplied hex key. It will scarify a garden, but the rattly chassis and frame make it no pleasure: the clumsy 41 cm working width is too light, it bumps across the surface at 12 mm of depth, wanders off line and needs constant attention. Noise is high enough to get the whole street out of bed. The bag is large and fills quickly with sand, at which point the light machine tips over backwards. Search Amazon UK · Search Amazon US
Costway QF32204DE — cheap and badly built, with a wobbly handle assembly, an unreinforced polypropylene flap and thin plastic wheels from the very bottom of the manufacturing scale. Central height adjustment, an aerator roller and a bag are at least included. It scores to 12 mm, but it is too light, so it bumps off line repeatedly and the handle has to be held firmly down throughout. Noise carries across the neighbourhood. Search Amazon UK · Search Amazon US
Bosch UniversalRake 900 — an electric rake, no more and no less: an aerator, not a scarifier. A plain iron rake is sturdier and longer-lived, and the materials used for the wheels, the height adjustment, the quick-release screws and the box are from the bottom drawer, with the push-together box a nice idea undermined by a wobbly joint. Among the few advantages is the same air-driven collection principle as the Bosch scarifier: air throws light moss and weed into the box while the bulky drum keeps stones and much of the sand out. Noise is moderate, and on the low side by comparison. Search Amazon UK · Search Amazon US
Scarifying a lawn: the horticultural bit
Whether a lawn needs it is easy to check. Pull a small metal rake loosely through the grass; if moss or other residue comes away with it, the lawn is ready.
Areas up to about 100 m² are best done by hand with a hand scarifier. Above that a powered machine earns its keep, and it is worth working without the collection box and picking the moss up afterwards with an iron rake — that leaves the soil and dead plant matter on the lawn, and the composting effect feeds the soil life that produces the nutrients the grass lives on. On badly mossed ground the box is full in no time anyway.
Technique matters more than the machine. The lawn should be dry beforehand, so not straight after heavy rain. Mow first, to around two centimetres, shorter than usual, so the machine has an easier job and does not strip out extra grass. Keep moving briskly rather than dwelling in one spot, which can damage the sward. Work in lengthways passes and then across, so nothing is missed; zig-zagging as you might with a mower is a poor idea at a deep setting, and reversing or turning tightly is worth avoiding for the same reason. Rake the ground over first if large stones are lying about. Afterwards, clear the loosened thatch and moss away thoroughly, reseed bare patches, and consider a layer of lawn lime around two centimetres deep to improve the soil's air balance.
Spring is the usual time, most often April, and the conditions matter: ground fully thawed, no hard frosts still to come, the lawn not dried out, temperatures between 10 and 20 degrees. If the lawn gets heavy use it is worth having the job done by May, since it deserves a few weeks to recover first, and it can be repeated in autumn if needed. Aerating, by contrast, can be done at any point from spring to autumn and without mowing first, because no grass roots are cut. Feeding a fortnight beforehand helps the lawn grow back faster.
Moss and thatch: fixing the cause
Scarifying regularly achieves little if the reasons for the moss are left in place. Moss is more adaptable and less demanding than grass: it loves nutrient-poor, compacted clay soils and acid, lime-deficient ground, shade and persistent damp suit it, and it survives heat better than grass, so when the lawn scorches the moss reappears.
Grass wants the opposite. It hates waterlogging and prefers a sandy, light soil with little clay; lime regulates the pH and makes the ground unattractive to moss; it needs sun, and its nutrient deficits corrected by regular feeding. Autumn leaves should be cleared promptly so the surface can dry, permanently shaded lawn areas are best avoided, heavy ground may benefit from drainage, and cutting too short is a mistake — the plant needs about four and a half centimetres of blade to photosynthesise.
Thatch is what accumulates when mulch — clippings and other dead plant matter — is left on the surface. Mulch-mowing produces a lot of it, and so does a robot mower running every couple of days. Nothing is inherently wrong with that, since the clippings rot down and return nutrients, but they do not rot completely, and depending on moisture, lawn height and density, material is left behind. When too much builds up, that thatch soaks up moisture and blocks the supply of water, air and nutrients, which weakens the grass and lets weeds and moss take over.
Assembly, storage and upkeep
These machines arrive in more or less compact cartons and need putting together, which is generally quick: the handles bolt together with wing screws and sometimes quick-release catches, plus occasionally a control handle and a little fixing hardware. The collection box, where supplied, is a plastic mesh with a grid frame slotted into it.
Electric machines are largely maintenance-free — a wipe of oil on the blades before they are put away stops them rusting. Every scarifier in the test has folding handles, so once the wing screws are undone the frame folds down, which matters for a tool used twice a year that spends the rest of it in the shed.
How they were assessed
Corded electric, cordless and petrol machines were all included. Every scarifier was run on a large lawn left heavily mossed by the winter, under comparable conditions. The assessment covered the result on the ground, handling, build quality and value. For cordless machines, runtime at a medium working depth was recorded against the battery capacity used. Smoothness of running and behaviour on uneven ground — including on contact with harder material in the lawn — were checked, and the evenness of the cut pattern fed into the score.
Because these are seasonal tools, the options for compact storage were assessed, with folding mechanisms, joints, quick-release catches and hand screws examined for function. Ergonomics formed another test point, in particular whether a machine adjusts to different heights of user, and collection boxes were judged on stability and on handling when emptied. Servicing effort was the final element, above all cleaning the roller and blades, which collect plant debris in use.
The test lawn was no showpiece: nutrient-poor, lime-deficient and neglected, partly heavily mossed, bumpy and uneven — a fairer test of a scarifier than a manicured surface would be.
The short answers
Which lawn scarifier is best? The Husqvarna S 138C for most people. The cable makes moving about less than effortless, but the build quality does not suffer for the machine's modest positioning and the handling is particularly comfortable. Several other corded machines also did well, and cordless models are now making inroads.
How deep should it be set? A few millimetres is enough to pull out moss and dead plant material. If there is a lot of leaf litter, wood or pine cones about, a scarifier will collect it — run a setting at which the blades do not yet enter the soil, using the aerator roller if need be.
Is it worth scarifying a mossy lawn in shade? As long as the sun reaches it for at least half the day, it can be. Special feed and a generous dose of garden lime should go on as well: moss points to acid soil, and lime neutralises it.
Is a cordless machine worth it on a small, awkward plot? With plenty of curves and corners a cable is a real irritation, so yes — provided you can run other tools from the same batteries, or split the cost of machine, battery and charger with a neighbour, since it is a lot to lay out for something used twice a year.
When should you buy petrol? Not on area alone, but on how that area is broken up and how many outdoor sockets there are. For a 1,000 m² lawn with a socket at every corner, a good corded machine is the better answer: you move the plug a few times and drag the cable behind you, and in exchange you skip oil changes, refuelling and a machine that will not start. If that same area is heavily broken up by buildings and shrubs and the sockets are not there, petrol makes much more sense.
Is a cheap corded machine enough? On a small lawn, in theory yes. In practice low-end models are no pleasure to work with, quite apart from the sustainability of a tool that breaks after a few years. The details separate them: protection against stone strike, metal or reinforced box mountings, rubberised or reinforced wheels, and folding handles with locking levers you can trust. A powered machine is worth having — hand scarifiers are usually not worth the effort.
Where do cordless machines run out? They have little power, so they only lightly score the surface. A deep setting of -10 to -15 mm is beyond a battery machine, and emphatically so in heavy, densely rooted soil.
