Why Is My Leylandii Going Brown? (and Can It Recover)

By Paul Watmore, Director at Grasslands Nursery

Brown Leylandii is usually down to one of five things: cutting into old wood (which never regrows), drought, waterlogged roots, conifer aphid, or shading — and whether it recovers depends entirely on whether green growth remains. Leylandii cannot reshoot from bare brown wood, so the key is to find the cause and protect the green.

1. Cut into old wood (permanent)

If the brown appeared after trimming the sides too far, this is the cause and it will not recover — Leylandii does not reshoot from bare wood. Always trim within the green. There is no fix except to live with it, screen it, or replace.

2. Conifer aphid (the sneaky common one)

Conifer (Cinara) aphids are a very common cause of Leylandii browning, usually in spring and early summer. The browning typically starts on the older, inner and lower growth and spreads, and you may see sticky honeydew and the large aphids themselves. Treat promptly — the green tips usually recover, but bare brown patches left behind will not green over.

3. Drought and establishment stress

Newly planted Leylandii and hedges in dry spells can brown from lack of water. Water deeply and mulch — green growth will usually recover.

4. Waterlogged roots

On wet, poorly drained ground the roots can rot, browning the foliage from the base up. Improve drainage; badly affected plants may not recover.

5. Shading

Where a hedge is shaded on one side or crowded, the shaded growth thins and browns. Keep it narrow and let in light.

Can brown Leylandii recover?

It comes down to one thing: green recovers, bare brown wood does not. Fix the cause (water, drainage, aphids), protect the green growth, feed in spring — and if the browning is bare wood from over-cutting, the realistic options are to screen it or replace. If you are replanting, Thuja regenerates from old wood and is more forgiving.

Browse our Leylandii hedging and conifer hedging, or see how to cut a Leylandii hedge.

FAQs

Why is my Leylandii going brown?
The common causes are cutting into old wood, conifer aphid, drought, waterlogged roots, and shading. Aphids and drought often brown the inner and lower growth in spring and summer.

Can Leylandii recover from brown patches?
Only where green growth remains. Leylandii does not reshoot from bare brown wood, so patches caused by over-cutting are permanent, while aphid or drought damage on green growth usually recovers once treated.

Why is my Leylandii brown in the middle or at the bottom?
Browning of the inner and lower growth in spring or summer is often conifer aphid; it can also be shading or drought. Check for sticky honeydew and large aphids.

Will brown Leylandii grow back?
Green growth recovers once the cause is fixed, but bare brown wood will not reshoot. If it is bare from over-cutting, screen or replace it.

About the author: Paul Watmore is a director at Grasslands Nursery, a family-run plant nursery near Knutsford, Cheshire, growing hedging, pleached trees and specimen plants since 1984. Meet the team →