Hedge Trimmers

Cordless Hedge Trimmers

Cordless Hedge Trimmers

This most recent of the Hedge Trimmer types has also seen probably the most development
work on the part of manufacturers, and the greatest improvement in machine capabilities.
At the heart of this innovation lie the new types of battery that are available. The types used
now are either Nickel Cadmium (NiCd) or Lithium Ion (Li-ion). Former problems of
‘memory effect’ that used to shorten effective battery charge life have been banished. They
are lighter, more powerful, charge quicker and last longer.

Hedge Trimmers

Hedge Trimmers

Generally speaking NiCd is used in cheaper models and the more expensive and powerful Liion batteries are deployed in higher-specification machines: but this is not an infallible guide to performance.

The small Bosch 16” has a 14.4V (NiCd) power rating rather than the 18V normally found on
others but it boasts the longest running time of its class at 55 minutes (others manage less
than 30 minutes).

A feature worth looking for when choosing a cordless hedge trimmer is a pivoting head or
rotating handle, which allows you to cut precise angles or vertical faces easily. This sort of
function is built in to the Black & Decker hedge trimmer 20” model and the Gardena 19”
Ergo Cut.

Mows The Grass

Mows The Grass

Because batteries are expensive and more and more cordless tools are appearing, it is high
time that there was some standardisation in the power packs and their charging apparatus.
Two manufacturers that have grasped this nettle are Ryobi and Bosch, who offer units that
will power not one but many compatible machines of different functions, such as drills and
chain saws. Ryobi call their initiative the ONE + concept. Their latest charger will work on
either type of battery.

Check, by the way, that your chosen machine does include a battery: if you do not read the
advertisement closely you may find that the surprisingly good headline price for a smart
machine may in fact be because it is battery-free.

Weight may be an issue for some users who do not pump iron and would rather avoid
repetitive strain injury. The latest designs from Bosch have aimed for weight reduction and
have gone down by 30%: they are achieving as low as 2.2kg, whereas others weigh in at
more than 4kg in the same sub-18” category.

Ergonomic cordless trimmer design

Ergonomic Cordless Trimmer Design

Ergonomic Cordless Trimmer Design

Other nice-to-have features in your trimmer are good ergonomic design that incorporates
soft-grip handles: low vibration (such as Black & Decker offer with their asymmetric blade
design) and it is worth checking that the blades are laser-cut and diamond ground for
maximum effectiveness.

Be aware that after your cutting session of (usually) 30 to 50 minutes, you are in for a lengthy
charging period. You can of course avoid this problem by acquiring another battery and
charging it offline. However you should also see how long your planned machine requires for
a recharge. Most manufacturers quote 3 hours for their 18V units. One notable exception is
Bosch, which offers two different novel solutions.

Their 20.5” machine carries a twin pack of 14.4V (1.5 amp-hour) batteries. By this means it
achieves a running time of 70 minutes (2 x 35 minutes per battery) and a recharging is made
easier using standard Bosch units charged offline while you work.

Cleverer still is the 21” premium model that has a 36V Li-ion battery, a 50 minute run time
and charges itself in just 45 minutes: if you are really in a hurry it will be 80% recharged in
25 minutes. Barely enough for a coffee break.

Bosch hedge trimmer

Bosch Hedge Trimmer

Bosch Hedge Trimmer

This same Bosch hedge trimmer model adds features like 20mm blade spacing and a sawing
function at its tip which means that branches of up to 25mm diameter can be despatched,
something that previously was unthinkable from a cordless hedge trimmer. An electronic
anti-blocking feature protects the machine from damage. There is also an extra protector for
safe cutting along edges of walls or near the ground.

Right at the top end of the cordless market, in terms of size, specification and price, is the
professional 21.5” Makita. This achieves the same 36V as the Bosch by packing two 18V Liion batteries. It claims a lower than usual noise level of 86.5dB (these are not quiet machines even in electric form due to their high-speed reciprocating blade mechanisms). It also carries features that include a battery protection circuit, and protection from over-discharge, high
temperature and overloading. These are very wise precautions because Li-ion batteries are
more prone to damage as a result of such abuses.

Bosch Garten ASB

Bosch Garten ASB

Most machines sold in this market are the smaller ones with blade lengths of under 20 inches.
In this mainstream sector it is worth mentioning the models from German garden equipment
specialist Gardena. In addition to their typically well-designed and constructed Easy Cut
19.5”, which has a large starting button for easy operation, they have an Ergo Cut version
with relatively wide blade spacing of 16mm to deal with thicker growth than you can
normally tackle. (Most competing models are for light duties and have tooth spacings of
10mm to 12mm). The same model has a blade protector.

Conclusion

Garden Gasoline Scissors

Garden Gasoline Scissors

For most users in the hedge trimmer market, there is a cordless hedge trimmer model that will
suit: and when you add into the equation the extra safety of not trailing a live cable near a
cutting device, and it makes the cordless route a very attractive one.

How to Choose

How to Choose a Hedge Trimmer

How to Choose a Hedge Trimmer

How to Choose a Hedge Trimmer

How to Choose a Hedge Trimmer

Back in the 1970s, your choice of hedge trimmer was pretty simple.

If you were a home user and you wanted to keep control of your privet hedge, you bought a
Black & Decker electric trimmer with a long lead.

On the other hand if you were a professional groundsman doing heavier work and often
operating in a park well away from any shore power, you selected one of the early 2-stroke
petrol-engined machines from the likes of McCulloch.

Nowadays, your choice is far greater. How do you determine which type of machine to buy,
and what are the differences between brands?

In terms of types, you have three choices.

Cordless Hedge Trimmers

Cordless Hedge Trimmers

Cordless Hedge Trimmers

This is the newest segment of the market and probably the fastest-growing. The revolution in
battery technology, spurred on by automotive research, has brought us new types like Nickel
Cadmium and especially Lithium Ion, which have lower weight, quicker charging, longer life
and greater power than ever before, so that a whole new range of machines can now be
effectively powered by these means.

Most cordless trimmer motors run on 18 volt batteries, but at the top end brands like Bosch
and Makita offer really powerful 36V models. The cordless trimmers offer a range of usable
time from 30 to 55 minutes. Charging typically takes 3 hours but some models using the
latest fast chargers and Li-ion batteries are achieving sub-1 hour times: a premium Bosch
model claims just 45 minutes.

Although battery hedge trimmers are generally used for light duties, some do offer wider
cutter gaps (of some 15mm rather than 10mm) which are normally more associated with
powerful machines. In association with a strong motor, this allows mature hedges and shrubs
with medium diameter stalks to be cut without jamming the machine.
The specialist short-cutter shrub cutting trimmers / garden shears are generally cordless
devices and battery power is perfect for this application.

Corded (Electric Hedge Trimmers)

Corded (Electric Hedge Trimmers)

Corded (Electric Hedge Trimmers)

Machines with cables attached obviously have an Achilles heel when compared with their
battery brothers, but if the work that you intend to do is likely to be within reach of a heavy duty cable extension then you may elect for the traditional mains-powered hedge trimmer.

With 240 volts and much greater torque, these trimmers can cope with rougher treatment.
They are also lighter to hold, not having to carry a battery: an average sub-18” cutter-length
machine is between 2 and 3 kg compared to 4 kg or more for an equivalent cordless.

This allows greater tooth spacing – from 16mm on smaller machines to as great as 34mm on
the biggest Bosch machines, which permits small trees to be pruned. Hand in hand with this
is the greater cutter bar length that can be offered: there is a range of sizes right up to 750mm
/ 29.5”.

Check the length of cord supplied with a machine – many have 10 metres but some supply 12
metres. If using an extension, make sure it is a 13 amp one with a thermal cutout. And always
purchase an RCD breaker to protect yourself against any accidental cable cutting.

Petrol Hedge Trimmers

Petrol Hedge Trimmers

Petrol Hedge Trimmers

Petrol power (or gas power for US readers) is still popular because it offers the same go anywhere capability as cordless electric, plus the ability to keep on working so long as you have brought along a relatively small amount of spare 2-stroke mix (of petrol and oil).

All the same features are on offer from manufacturers as in the electric sector of the market.
The potential downsides are the pollution of the engine (despite recent improvements from
most manufacturers) and sometimes, the difficulty of starting the engine with the pull-cord.
Extremes of temperature, rain or snow, and high altitude can all adversely affect the
willingness of the engine to start.

This makes the models that offer easy starting attractive. This includes those from Hitachi
with its ‘S-Start’ or McCulloch who offer a fuel pump that reduces the starting effort.
Petrol machines with their self-contained power plant and tank are a bit heavier than any
other kind, ranging from a lightweight McCullough model at 5.1kg to up to 7kg in some
models.
One aspect to remember is that petrol-engined machines are noisy: they can be over 100dB
beside the machine and operators must wear ear defenders. Those with nearby neighbours
should also think about the noise nuisance factor.

Petrol Hedge Trimmers

Petrol Hedge Trimmers

Whereas most big-selling electric models are typically 400W in power, rising to around
700W for the most powerful Makita, petrol machines are all relatively powerful: the excellent
21.1cc Hitachi engine has 740W. And petrol machines top the size league, with bar lengths of
up to 31”/780mm in the case of an extra-long Hitachi 23.9cc/ 810W model.

When buying a machine, look at the fuel tank size: the domestic-use McCullough model has
0.2 litres but professional units have 0.6 litre tanks that allow long uninterrupted periods of
use.

On all types of trimmer, a very useful feature is a swivelling rear handle that allows vertical
or angled trimming to be carried out much more easily and accurately. There are various
types of arrangement: Draper hedge trimmers have a patented 5-position rotating handle.
Long-reach models can be bought in electric or petrol types: they are specialist machines but
very useful for tall or awkward hedges and shrubs.

So in the modern market there is something for everyone: some makers like Bosch, who offer
home user and professional models, seem to cover every little niche. Get professional advice
and you will find a machine that suits you and your hedge right down to the ground.

Types of blades

Types of Blades

Types of Blades

Hedge trimmer blades range greatly in length, and again the one which is suitable for you
will be dependant upon the work you will be carrying out. The smallest blade is six inches
and is usually used for detail work on small hedges or topiaries. It is advised that in the
normal family setting a gardener would not need a blade larger than eighteen inches. At the
other end of the scale you have the 28 inch blade. These are obviously used in tandem with
the heavier trimmer (and by default the petrol trimmer) and are largely found in commercial
settings.

You should be aware that the longer the blade the heavier it will be and so the harder it will
be to control. If you are considering working with the larger blades (and trimmers) ensure
you feel safe with it before use

The History

The History of the Hedge Trimmer

The History of the Hedge Trimmer

Hand Shears

Hand Shears

Hedge trimmers have been needed for as long as hedges were first used to delineate fields
and to protect crops and animals from excessive sun, wind, driving rain or snow.
Hand shears were the weapon employed for centuries, but in the innovative 19th century
there were many attempts to invent labour-saving devices for use out in the fields, and some
of these are enshrined in patents. Then in the 20th century, the populace started to acquire
gardens and a whole new requirement arose.

The timeline of key years in hedge trimmer development is shown below.
1854 Leonard Wood of Idaho proposes a device whose travelling wheels carry it alongside
the hedge but also drive gearing that activates the ‘nearly vertical’ cutter wheel and the
horizontal cutters. Like all devices of its period this relies upon horse-drawn propulsion, or
later, steam power, but hand-held devices are a long way off.

1865 A. Selover patents a wooden construction which still relies upon a saw but has
adjustable clamps and screw rods to control the height and width of the cut.
1871 James and Oliver Vannosdall patent another framework device.

Extended Reach HedgeTrimmer

Extended Reach HedgeTrimmer

1890 Andrew Fox of Dayton Ohio invents a machine with a base unit with an inverted V
hood shape and a series of cutters at the front edge. This is beginning to get closer to the idea
of multiple blades that we see today.

1891 Robust Elliot patents what he calls a ‘portable’ device but it is a truly scary-sounding
unit of torture which requires the poor operator to be fastened to an endless traveling cable,
supported at either end of a field and ‘kept in motion by any suitable power’. This
demonstrates that it would take the invention of small lightweight motors and frames for
there to be a modern hand-held device.

1922 The Little Wonder company of the UK launch a hand-cranked hedge trimmer. This is
the first of the modern-day hand-held reciprocating-blade devices as we know them. It stays
in production right through to the 1950s and becomes a rapid hit not just with horticulturalists
but with pasta makers! The razor-sharp blades prove to be ideal for delicately slicing the
hand-made strands. In 1935 the company was bought out by Schiller of the USA and moved
there: they still manufacture in 3 US plants.

1940 Little Wonder launch the first single-blade reciprocating electric hand hedge cutter.
1945 They add the first double-blade reciprocating cutter.
1955 They bring out the first-ever petrol-engined model.

Plant Trimmer Hedge

Plant Trimmer Hedge

Baby Boom

Thereafter, the post-war development of these machines is reminiscent of that of chain saws:
the same manufacturers began to bring out smaller, lighter trimmers based on the new alloys

and using 2-stroke motors for the petrol models. There was a greater emphasis on electric
motors from the start, in volume sales terms these being essentially garden devices rather
than remote outdoor machines like chainsaws.

One very notable brand in hedge trimmer history is Black & Decker, which was a leader in
popularising this new electronic gadget with homeowners. As early as 1962 they brought out
a version with a self-contained battery power pack. However it would take further
developments in battery technology before truly satisfactory performance could be achieved.

In the modern market, the cordless sector is firmly established, with B&D and other brands
including Bosch, Makita, Einhell and Ryobi offering a range of sizes and power levels.

Hedge Trimmer

Hedge Trimmer

Black & Decker’s pre-eminence in electric drills led them in the 1970s to bring out
attachments which included a hedge trimmer unit, but it was not as versatile as a bespoke
machine.

McCulloch, one of the chainsaw pioneers, diversified into hedge trimming in the 70s.
Nowadays they are owned by Husqvarna, the world’s largest producer of outdoor power
products, and you can buy their various models under the names of Husqvarna, McCulloch,
Gardena and others. McCulloch continue to innovate in the petrol sector, with a fuel pump
for easy starting and very lightweight 5kg petrol machines. (Most are 6, 7 or more kg).
Leading gardening brand Gardena is the name for the cordless range, including long reach
models.

An important new feature was invented by Echo, who created the first long-reach trimmer
that articulated to allow users to shape hedges in high and awkward places.
Today, many top-end models have pivoting handles that bend to allow
different angles to be more easily achieved when cutting.

The shape of things to come

Idea Concept

Idea Concept

Innovation never ceases: as recently as May 2011 a US Patent was granted to Techtronic
Outdoor Products Technology for a Multipurpose Debris Deflector. Most machines can
sometimes throw the waste at you or in all directions so this, and similar devices that are
beginning to appear, are welcome.

Such safety improvements are an important factor: for example it is now mandatory that both
hands have to be on the handles before the device can function. New cut-off devices have
appeared as a result.

Development in the petrol engine field has been spurred on by Governments, notably in the
USA. Two-stroke motors are light, do not require an oil tank, and have the advantage of
being able to operate at all angles including upside down. Their own downside is their poorer
emissions record when compared to a 4-stroke as used in cars.
Ryobi have brought out a ‘No Mix 4 cycle’ motor that meets the toughest (Californian)
regulations. It claims to work in all positions as well. Initially applied to string trimmers
(‘strimmers’), it will surely transfer to hedge trimmers.
3

Mc Connel Power Arm Versi

Mc Connel Power Arm Versi

Within the 2-stroke engine market, improvements are also being made. Back in 1998 Tanaka
claimed their new motors were 70% lower in emissions than previously. Briggs & Stratton
and other established makers are gradually working to lessen their carbon footprint and to
meet the much tighter State air pollution restrictions.

Outside the scope of this article, there is the continuing use of hedge trimming devices that
attach to tractors, and in the commercial farming and parkland sector these take care of the
vast majority of hedges.

Wherever they are in use, the hedge trimmers will continue to shape our landscape and it is
hard to see them going away in our lifetimes.