Invasive plants and tree disease
Leylandii: too tall? your options, rights and what it costs
Leylandii is a fast-growing conifer often planted for hedges that quickly becomes very tall and blocks light if not regularly trimmed. It is not invasive, but height and neighbour disputes are common. You can trim or reduce it, and the High Hedges legislation gives councils a role where a hedge unreasonably blocks a neighbour's light.
- Also known as
- Leyland cypress, Cupressus x leylandii, x Cuprocyparis leylandii
- Easily confused with
- other conifers (Thuja, Lawson cypress), western red cedar hedging
- How serious
- Low risk to property; high for neighbour disputes over height and light
- Typical cost
- Routine trimming is modest; full reduction, felling and stump removal are priced by height, length and access
How to identify leylandii
Leylandii is a dense, fast-growing evergreen conifer with flattened sprays of small, scale-like, dark green foliage, commonly grown as a tall hedge or screen. It can put on a substantial amount of growth each year if not cut.
It is usually recognised by its rapid height, dense year-round cover and the brown, bare interior that develops if it is cut back hard into old wood, which it does not readily regrow from. The RHS provides guidance on growing and pruning leylandii hedges.
How serious is it?
Low risk to property; high for neighbour disputes over height and light
Leylandii is not invasive or hazardous, but it causes more neighbour disputes than almost any other garden plant because of its height and the light it blocks.
The law recognises this. gov.uk explains the High Hedges provisions of the Anti-social Behaviour Act 2003, under which a council can intervene where an evergreen hedge over 2 metres unreasonably affects a neighbour's reasonable enjoyment of their property, usually as a last resort after neighbours have tried to resolve it themselves.
How to fix it yourself
- Trim regularly. Leylandii responds well to routine trimming of the green growth to keep it at a manageable height and width; the RHS recommends regular light cutting rather than letting it run away.
- Reduce height gradually where possible. Be aware that cutting into old brown wood usually will not regrow, so a very hard reduction can leave bare patches.
- For tall hedges, use proper access equipment and protection, and check for nesting birds before cutting, as it is an offence to damage active nests.
- Where the issue is with a neighbour, talk to them first; gov.uk treats the High Hedges complaint process as a last resort after reasonable attempts to agree.
- Decide between reduction and removal based on how much usable green growth remains and how much light or space you need to recover.
When to call a professional
- Tall hedges needing height reduction or felling, which involves working at height and removing large volumes of material.
- Where you want a clean removal and stump grinding, or advice before a High Hedges complaint.
Who to call
- A tree surgeon or hedge-cutting contractor, ideally Arboricultural Association (ARB Approved), for reduction, felling and removal.
- Your local council, for the High Hedges complaint process where a neighbour's evergreen hedge over 2 metres unreasonably blocks light.
Indicative cost: Routine trimming is modest; full reduction, felling and stump removal are priced by height, length and access. Prices vary by area, severity and access, so always get a written quote.
Frequently asked questions
How tall can a leylandii hedge be legally?
There is no fixed legal height limit, but gov.uk explains that under the High Hedges rules a council can act where an evergreen hedge over 2 metres unreasonably affects a neighbour's reasonable enjoyment of their property. It is treated as a last resort after neighbours have tried to resolve it.
Can I cut back my neighbour's leylandii?
You can generally trim branches and roots that cross the boundary onto your property, back to the boundary line, but you should not enter their land or kill the hedge, and cuttings belong to the tree owner. For height and light issues, the High Hedges process through the council applies.
Will leylandii grow back if cut hard?
Leylandii does not reliably regrow from old brown wood, so cutting back hard into bare interior wood usually leaves permanent bare patches. Regular light trimming of the green growth keeps it dense and manageable, which is why staying on top of it matters.
Should I reduce or remove an overgrown leylandii?
It depends on how much living green growth remains and what you need. If there is enough green to keep a tidy face after reduction, reducing it can work; if it is bare and unmanageable, or you want the space and light back, removal and stump grinding may be the better option.
Sources
Editor, HomesAndHedge
Oliver leads HomesAndHedge's editorial coverage of home and garden problems. He researches and writes the plain-English explainers on pests, invasive plants, damp and mould, drainage and wildlife, drawing on guidance from bodies such as the Property Care Association, the RHS and the NHS, and is clear about when a job needs a qualified professional.
Last reviewed: 8 June 2026