Table of Contents
Trimming a Hedge Means Two Different Things
Trimming a Mature Hedge: Cut off practically all the new growth (less than a year old), in order to keep a mature hedge at the desired size. It’s like shaving back to the same line every time.
Trimming a New Hedge: Cut off the tips of all the shoots*, pruning back thin or straggly stems, to maintain bushy, even growth while the hedge reaches the desired size.
Formative hedge pruning lasts for the first few years.
*Except conifers like Yew, where you trim the sides but leave the tip at the top of the leading stem intact until it’s a clear 15-30cm above the intended final height of the hedge.
- Trimming stops a plant’s tendency to produce tall, upright shoots that would eventually become branches and trunks in an overgrown hedge
- Trimming forces the hedge plants to produce bushy growth down to the base
How Often Do I Need to Trim?
- Formal garden hedges: Usually twice a year for a tidy, sharp look. Really vigorous species like Leylandii can be trimmed three times. Just like shaving a face, it’s easiest to trim when there is only a light bit of regrowth.
With that said, many hedges such as Yew and Privet are widely trimmed once a year, especially in shady locations & poor soils where growth is slower. - Native countryside hedges: Tractor-mounted flails are typically used every other year to maintain farm and roadside mixed hedges. If you have a mixed native hedge in your front garden, then one annual cut between late Autumn and early Spring is best for wildlife, while keeping it quite tidy.
Clipping in Spring or Summer especially slows down growth, which really helps to keep vigorous evergreen plants at the desired size.
What You Need to Trim a Hedge
- Tools for Trimming:
- Small Hedges & Soft Growth: Hand shears are simple to use and relatively safe.
- Larger Hedges: Electric, petrol, or cordless hedge trimmers but please take care and wear the right kit.
- Large-Leaved Evergreens: Secateurs or loppers for a cleaner cut.
- Equipment: Sharp tools are essential and make the job easier.
- Safety Tips:
- Protective Gear: Wear safety goggles, thick gloves, and – recommended – ear defenders.
- Using Ladders: Ensure they are stable. Tripod ladders are ideal for uneven ground. Have someone hold the ladder as well.
- Safety Guides: Common sense helps and always follows the safety guide fo the tool you are using.
- Pre-Trimming Check:
- Bird Nests: Inspect the hedge for nests, especially between March and August. You are required by law to delay hedge trimming if nests are active.
- Safety Issues: Check for fence posts and fencing hidden in the hedge
- Necessary Equipment:
- Hand shears or powered hedge trimmer
- Residual current device (RCD) for corded trimmers
- Secateurs or loppers
- Sturdy boots, thick gloves, and safety goggles
- Ear defenders (optional)
- Canes, string, rake, or broom
- Tarpaulin or old sheet (optional for collecting trimmings)
How to Trim a Mature Hedge Step-by-Step
- Assess Your Hedge
- Walk along the hedge to identify uneven growth.
- Aim to remove nearly all growth less than a year old.
- Use a straight edge like a lawn edge, paving, or a ground-level string line as a guide.
- Preparing to Clip Your Hedge
- Clear obstacles and trip hazards from the area around the hedge.
- Laying a groundsheet out to catch trimmings makes for an easier clean-up, especially over gravel or bark chips.
- A corded trimmer must be plugged into a residual current device (RCD) for safety.
- Cut the Sides First
- Start from the bottom and work upwards, keeping blades parallel to the hedge sides.
- For hedges under 1 m (40 in) tall, keep sides vertical.
- Taper taller hedges to be slightly narrower at the top or add a 45° chamfer.
- If the top of a hedge is narrower than the base, it is easier for light to reach the lower branches to encourage their growth.
- Optional: Use a Garden Line for a Neat Top
- Stretch a string 1 cm (½ in) below your desired height between stakes at each end to give you a straight guide.
- On sloping ground, you can slope the hedge top, create steps, or keep it horizontal by allowing lower plants to grow taller. Your choice.
- If the top of your hedge is shaped, trim all new growth to leave about 1 cm (½ in) remaining and you will follow the original outline.
- Measure Twice, Cut Once
- Pause frequently to make sure you are trimming as planned.
- If you’re new to clipping hedges, take off small amounts in 2 or 3 cuts.
- Very few conifers (yew is an exception) regrow from old wood, so be extra careful.
- Clear Away or Mulch Trimmings
- Sweep clippings off the hedge with an upward motion to the top
- Collect trimmings using the material laid earlier
- The best use for hedge clippings is mulch, or dumped in an unused corner for wildlife
- Second best is composting: either shred them first to speed decomposition, or use longer term piles with layers of different “brown or green” plant matter, which means low or high in nitrogen
- Otherwise, we prefer the bonfire to a green waste bin, it’s up to you
After You Trim Your Hedge
- Mulching: As long as the soil is damp, put a layer of organic matter around the base of the hedge in late winter/early spring to help regrowth.
- Fertilizing: If your soil is poor or if your hedge looks underfed (yellowing leaves in summer) use a general-purpose fertilizer before mulching.
- Watering: In hot dry weather, water your hedge after trimming it, especially if it’s recently established. Ideally, we recommend watering the hedge a day in advance during dry weather.
Trimming a Large Overgrown Hedge with Only Hand Tools
Hedge trimmers are wonderful machines for routine maintenance trimming, but when a hedge is overgrown with thick branches, good sharp hand tools make light work of even heavy restorative pruning.
We stress sharp because if this is new to you, you may not know that pros working with hand tools all day will sharpen their hand tools every morning and again during the day at least once, then clean and oil them at the end of the day*.
This small investment makes tools last much longer, and your forearms less sore after a day’s work!
*To be fair, other pros just keep buying cheap new tools: for the price of a pair of Felco 13 secateurs, you could get about 7 of Screwfix’s cheapest