How to Use a Hedge Trimmer: Top Tips

When to Trim Your Hedge

The best times to trim your hedge depends on the type of hedge you have and whether it is a formal or informal shape you are after. You must also make sure that there are no nesting birds when you plan to trim your hedge. It is an offence under the Wildlife and Countryside Act 1981 to trim a hedge when there is a nest being built or being used by birds. 

Guides for Popular Hedging Plants

Evergreen

• Ilex aquifolium (holly) – Cut once during late summer
• Buxus sempervirens (box) – Cut two/three times during growing season
• Cotoneaster lacteus – Only after fruiting
• Prunus laurocerasus – Prune twice during spring/summer
• Lavandula (lavender) – Prune immediately after flowering

Conifers

• Chamaecyparis lawsoniana (Lawson cypress) – Cut twice, in spring and summer
• Taxus baccata (yew): Cut twice, in mid-summer and autumn

Deciduous

• Carpinus betulus (hornbeam): Once, in mid-to-late summer
• Crataegus monogyna (hawthorn): Twice, in mid-summer and autumn
• Berberis thunbergii – cut after flowering

Formative Pruning

Formative pruning is to be done soon after you have planted your hedge or bush and will dictate the shape you want. Deciduous hedges should be pruned in winter after planting, and evergreen hedges should be pruned in the spring. Both types of hedges should be pruned for the first two years to form their shape. 

Hedge Maintenance and Trimming

If you have a formal hedge, you will need to trim more frequently to maintain the shape. For the vast majority of hedge types, the summer is the best season for this, just be wary of any birds who may still be nesting. Some conifers and deciduous hedges may allow you to continue to trim into autumn, for example, the hawthorn and yew.
As a general rule, if you have a flowering or fruiting hedge, you should wait until after the flowers or fruit have grown before trimming. You may also wish to remove older stems or thin twigs at this time to encourage new growth. 

A few safety tips to bear in mind before you start

1. Check the weather

You should never cut your bushes or hedges in the rain, this is especially important when using an electric hedge trimmer.

If the weather is fine to work in, check your equipment is in good working order and not damaged in any way.

2. Wear appropriate clothing and footwear.

The clothing you choose should allow you to move freely, be sturdy and tight fitting. Your clothes should offer you some protection and not be liable to snag on the branches as you cut. You should also wear sturdy non-slip shoes to provide you with a secure footing when using your hedge trimmer. Goggles and gloves are also recommended.

3. Clear the area

Pick out any dead leaves or debris that may be stuck in your hedge. This will stop debris from jamming your hedge trimmer and make cutting a whole lot easier.

4. Is it safe to start?

Are there children or pets running around the garden? If so, rope or mark off an area or safe zone so that they cannot enter where you will be using the hedge trimmer. 
If you are using an electric hedge trimmer, ensure you have enough cable to reach where you need to go. If the standard cable that comes with the hedge trimmer is not long enough, you can attach an extension lead. Never use more than one extension cable at one time and always make sure that the cable doesn’t form a trip hazard.

How to Shape Your Hedge

Now you and your hedge trimmer are ready to start work. If you are using an electric hedge trimmer, ensure the cord is behind you and out of the way. By cutting away from the power source, it will ensure the cable is always trailing away from you.

Shaping a formal hedge can take some practice to achieve, but with a few simple tips, it will be much easier to create beautiful shapes.

-Achieving straight lines
Cutting by eye is incredibly difficult, and most gardeners prefer to use string to ensure their accuracy. Use two stout canes either side of your hedge and tie the string so that it is pulled taut between them. This will give you a good guideline to achieve your perfectly straight line. Canes or stakes will also act as a guide for vertical lines.

-Tapering
To ensure that light can reach the whole hedge, not just the top, you should taper the hedge very slightly so that the top is thinner than the bottom. Even the most vigorous hedges won’t exceed more than 60cm depth, use this as a guide for the broadest section at the bottom.

-Shaping
If you wish to achieve a more interesting shape, you can use cardboard or plywood cutouts to guide your hedge trimmer. This technique is especially good for making arches in your hedge. For a rounded cut, start around 3 inches from the top of the hedge and move the hedge trimmer away from your body and to the centre of the top of the hedge, using an angle to create the curve. Repeat this motion on the other side of the hedge.

-Shaping tall hedges
If you are cutting taller hedges and using a hedge trimmer with a telescopic pole like the Flymo UltraCut Reach 420,  you will need to extend the pole to the appropriate height and tilt the blade to a 90-degree angle. When using this, take care to avoid any falling debris as you are cutting.
 

Tidying Up and Hedge Trimmer Maintenance

If your hedges are large or require a lot of trimming, you may prefer to tidy as you go. Placing a sheet on the floor before you begin will allow you to easily collect the cuttings as they fall. Then you can easily pick them up to dispose of them in your garden waste bin, or add them to your compost heap.

After cutting your hedges, it is important that you clean your hedge trimmer. During cutting it is likely that sap and debris from the bushes has become stuck in the blades and teeth. Leaving this debris in the hedge trimmer will make it more difficult and less efficient for your trimmer to cut the hedges next time you need to do it.

Turn off the machine and place it on a suitable work surface. Gently remove any loose debris and, clean the blade following the manufacturer's guidance. If you are using a petrol hedge trimmer, you may be required to lubricate the teeth with an appropriate oil such as linseed oil. Always follow the manufacturer’s advice when cleaning the product to maintain its warranty.

To sharpen the blades of your hedge trimmer, release the blades and clamp the first one into a vice. Slide a metal filer at a 38 degree angle up the length of the blade from bottom to top. To test the sharpness, gently bring a piece of paper down over the blade, and if it cuts, your blade is ready. Apply linseed oil and move to the other blade. Once you have sharpened both blade, screw them back onto your hedge trimmer ready for use.