What causes brown patches on Leylandii hedge?
Christopher Pierce
Published May 28, 2026
What causes brown patches on Leylandii hedge?
Over the past few years brown patches on leylandii hedges has been a real problem in some areas. These patches are caused by conifer aphids that feed by sucking the sap from the new shoots.
Can Brown conifers recover?
The brown needles and shoots will be shed and behind them will come new growth. It may take a while, but your trees and hedges should be able to recover. Don’t be tempted to prune it out or ask someone to do it for you. So if you prune them now, you could cut back too far and the plant will never recover.
How do you get rid of brown spots on conifers?
The problem is many conifers do not regrow from old wood so if you prune to hard you will likely notice brown patches. Our advice is to trim lightly, 2 to 3 times a year between April and early August and then give them a feed in late winter followed by a mulch of well-rotted farm manure which helps retain moisture.
Why is my Leylandii dying?
Hearing the symptoms, it could be that your Leylandii has been attacked by a cypress aphid. This is a highly destructive insect that sucks the sap out of the leaves. This causes the leaves to turn brown, eventually killing branches and ultimately the entire tree.
Do Leylandii need lots of water?
Newly planted Leylandii hedges need watering at least once a week during the growing season (March to October) and more often in hot and dry weather. Even if it rains, the plants may not be getting enough water. Water around the roots of the plant, not the leaves.
Does Brown Leylandii grow back?
Leylandii is one of the fastest-growing hedges available at 75-90cm per year. However, Leylandii hedges do not grow back in all circumstances. If the hedge is brown, new buds will not reappear as these branches have already died.
What will kill Leylandii?
Using Caustic Soda. The way to do this is to leave a stump by cutting the trunk and then killing the stump by digging around the roots and slinging caustic soda into that part. Remove loose limbs from the plant before falling it. Loose limbs may cause injury.
What is wrong with Leylandii trees?
With more frequent storm events damaging branches, and irregular rainfall patterns developing, the viability of a Leylandii hedge decreases. Cypress canker is spreading in Australia and the Monterey and Leyland Cypress are particularly susceptible.
Can you overwater a Leyland cypress?
Leyland cypress trees need very little care. Water them deeply during prolonged drought, but avoid overwatering, which can lead to root rot. The tree doesn’t need regular fertilization.
What to do about brown patches on leylandii hedge?
Our leylandii hedge has brown patches that are now spreading. Is there any remedy? Colin Evans, Merthyr Tydfil, Glamorgan Conifer hedges have been badly afflicted in this way over the past few years.
Why are the leaves on my leylandii turning brown?
These patches are caused by conifer aphids that feed by sucking the sap from the new shoots. In this gardening tutorial, Martin Fish from Garden News shows you how to deal with brown patches on your Leylandii hedges. If playback doesn’t begin shortly, try restarting your device.
When is the best time to get rid of brown patch?
Brown patch fungus can take hold of your lawn during the humid, hot weather in the summer. However, with the right timing and the right product, you can get rid of brown patch and begin to heal your damaged lawn.
What should I do if my leylandii plant rots?
If you have a heavy clay soil, make sure you break up the soil when planting Leylandii so any excess water can drain away, otherwise you can create a clay bowl for the water to collect in. The roots of Leylandii will rot when they sit in waterlogged conditions for extended periods of time.
How to stop brown patches on my leylandii?
They help grass to grow by aerating it, as long as the casts are not compacted, so brushing them is the best thing to do. They increase in autumn because the soil is wetter, but still warm. They indicate excellent soil health, so do not remove them! Our leylandii hedge has brown patches that are now spreading. Is there any remedy?
Why are the leaves on my leylandii hedge turning brown?
Over the past few years brown patches on leylandii hedges has been a real problem in some areas. These patches are caused by conifer aphids that feed by sucking the sap from the new shoots. In this gardening tutorial, Martin Fish from Garden News shows you how to deal with brown patches on your Leylandii hedges.
What are the treatments for brown patch lawn disease?
What Are the Treatments for Brown Patch Lawn Disease? 1 Irrigation and Moisture. Excessive moisture around the grass greatly contributes to problems… 2 Fertilization. Excessive or fast-release nitrogen fertilizer applications,… 3 Additional Care Considerations. Excessive thatch — the layer of living and dead grass stems,…
Brown patch fungus can take hold of your lawn during the humid, hot weather in the summer. However, with the right timing and the right product, you can get rid of brown patch and begin to heal your damaged lawn.