More threats to the horse chestnut
We reported in this blog back in May that Horse Chestnuts were under threat from the leaf miner moth (Cameraria ohridella) and the fungus (Guignardia aesculi). Not to mention the effects of drought!
Now there is another, greater threat to these stately trees – namely Bleeding Canker.
The first symptom is often an area of bark where a yellow / brown / red liquid seeps out. In the spring, this coloured fluid is usually transparent but in warmer weather it may become cloudy. When it is dry and hot, the flow may dry up - leaving a dark crust on the bark. However, the bleeding may start up again in the autumn. These observations have lead to the suggestion that the pathogen is most active when conditions are mild and moist (i.e. in spring and autumn).
Where the pathogen has been active, bark, cambial tissue and the phloem (the sugar conducting tissue) are destroyed. If this damage spreads around the trunk then more general effects will be seen, namely yellowing of the leaves, early leaf fall, failure to set fruit (no conkers!) and damage to the crown of the tree; branches may be weakened and fall. This sort of damage may well prove to be a major problem to local authorities as Horse Chestnuts are common in parks, streets and other public places. A recent
front page article in the Independent sought to raise public awareness of this issue.
It was thought that Bleeding Canker was caused by a fungal pathogen, possibly a form of Phytophora. However, research in the UK and the Netherlands (where perhaps 1 in 3 trees are affected) now suggests that a bacterium may be responsible for the disease.
The disease affects trees ranging in age from young saplings (10-15 years) to mature trees. Forestry Research Scientists have estimated that some 35,000 to 50,000 trees are already infected and the disease is quite widespread; just as the Elms were devastated by fungal disease in the 1970’s so Horse Chestnuts may be lost over the next decade.
The Research Agency of the Forestry Commission is collecting information about the spread of the disease: further information and survey forms can be found at their website.
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Discussion
we have a horse chestnut tree lined grove at clifton,
these were planted to replace the elms that were there origanally but were lost to the dutch elm desease.
the horse chestnuts now appear to have all the symptoms mentiond in you report,we estimate there must be over a hundred trees along with many other species
I have noted a sudden and savage deterioration in a huge number of Horse Chestnut trees near Colchester in Essex, namely in the villages of Birch, Abberton, Layer-de-la-Haye, Great Wigborough, Salcott-cum-Virley and along the entire road that leads to Tolleshunt D’Arcy and Goldhanger.
This is definitely Bleeding Canker but I have seen no mention of this problem in the local paper, the Essex County Standard.
I remember how this area was dominated by huge Elm trees until 1972 and 1973 when these trees were decimated.
On a visit to National Trust property, Waddesdon Manor, we were shocked and saddened by the sight of so many fine horse-chestnuts severely blighted by disease. The leaves were brown and blotchy, falling earlier than normal and there wasn’t a conker in sight. I predict the national Trust will have a huge task on its hands.
Try the Forestry Commission’s website http://www.forestresearch.gov.uk/fr/INFD-6KYC5F which has lots of info on horse chestnut disease.
We have Sweet Chestnuts grown from about 1ft, now about 30 years old. 2 completely dead, 1 really nice tree went sick last year, has died one side, several others are not looking too healthy. Lots of lower branches breaking off, completely dead, I put that down to lack of light lower down, but not sure now! This has happened quite suddenly in the last few years, and is shown by small leaves and not many of them, not growing out in to full size. Suspect we will take down about 8 this year, and am not expecting the remainder to last. Any ideas?
We pollarded our two Horse Chestnuts in the Autumn as firstly, we didn’t want them to get out of hand and secondly, the tree didn’t look that healthy and we were slightly concerned that they had a disease.
This spring the trees have re-shooted and look really healthy but I have just noticed this afternoon that several of the new shoots and their leaves have withered, died and turned black. They have then fallen from the tree. I have checked the other tree and the same appears to be happening.
Does anyone know why this is? I have checked the internet for info on Horse Chestnut disease and have seen a lot about bleeding Canker but the description and the photos don’t match what I have seen in my garden today.
[…] in 2006, the Woodlands blog commented on the problems facing horse chestnuts, namely disease ( leaf miner moths, leaf blotch […]
I live in Harlow, Essex and have 2 beautiful Chestnut Trees (Pink flower) at the bottom of my garden and several at the front of our row of houses. I have noticed over the past 5 years they have looked rather poorly and now realise they have been infected with the Miner Moth – I shall gather and burn the leaves this Autumn in the hope the trees will benefit and look healthier next year.
I see that most of our Horse chestnuts are very badly affected by this canker and blight in tha malvern hills area worcestershire very sad sight is there any likelyhood of a cure?
There’s a recent article here (see link below) urging people not cut down sick looking trees. There are three main threats (all mentioned in Chris’ article above) but they are not necessarily fatal. It seems that bleeding canker is the biggest threat in terms of killing off the tree. The leaf miner attack and Guignardia fungus attack make the leaves look bad but don’t appear to be killing the trees. The article states that people “can help reduce the spread of the disease by disposing of leaves during the autumn and winter and then composting them thoroughly.”
Every single Horse Chestnut I see here I Bishops Stortford (East Herts) has brown patches on leaves. Varies in severity but none seems to have escpaed completely. Got here via google – amazed this hasn’t been in the news more?! seems really serious.
Some have loads of conkers, some none, but they are starting to fall off and still white not brown inside.
A couple of months ago, I drove from Wimbledon to Barnes and noticed that all the horse chestnut trees looked very sick. Since then, I have been seeing horse chestnuts and oak trees in the same condition everywhere I’ve been including the whole of Richmond Park. I have heard nothing about this in the media. Incidentally, a very large elderflower tree also appears to have suffered the same fate but this may not be related. Other sprecies of trees appear to be vigorous and healthy so it seems unlikely to be drought.
Every tree in the Winchester area whose leaves are brown and half-dead looking is a horse chestnut; this is the 3rd year (at least) that I have noticed this, but nothing seems to be being done about it. Nor have I heard anything much on the radio, even though it is so obvious. If there are people out there researching into the cause (and, hopefully, a cure), I wish they would make their work better known. It is surprising that the trees manage to come into leaf at all. As far as I know, they are still producing conkers.
we have at least 100+ on our drive uop to the house infected with it. please let me know if there is anything we can do to save them, i had a,lso heard it was reportable, so therefore i will contact you and defra, i would appreciate ANY FEEDBACK . i, personally am quolified in horticulture, but we are all concerned about it with ttanks katharine pearse
I’ve noticed horse chestnuts all over the country with horrible brown spots covering the leaves; the ones near me had it last year, and the leaves came through OK in the spring but quickly got the same spots again.
The symptons of brown leaves on horse chestnuts described in earlier emails are common in the Watford area and we saw them last week in Essex and Suffolk. What is the problem and can any action be taken against it spreading further.
I have noticed many if not all horse chestnut trees in Suffolk appear to dying off with all leaves turning brown and it is only end of July. Are they diseased? Everyone else I have spoken too doen’t seem to have noticed until I pointed it out.
We have noticed many horse chestnut trees in the Milton Keynes area that are suffering badly like those described by David ie most of the leaves are brown. Young and older trees are both affected. This doesn’t sound like the symptons of ‘bleeding canker’ which seems to affect the bark, or other common problems like leaf blotch fungus or moth attack. Any ideas?
I have noticed this week in Oxfordshire that quite a few horse chestnuts have very brown sad looking leaves
After cutting down an infected tree – does anyone have advice for treatment of equipment?
I have just walked around Tooting Common and noticed maybe 20 or 30 Horse chestnuts in quite bad condition although I’m no expert but they do look sickly
[…] and sweet chestnut trees are common throughout the UK, though the former is presently under attack from moths, bleeding canker, drought and leaf blotch fungus. Like oak and beech, to which it is […]
See “Horse Chestnuts – under attack?” (May 2006) and follow Forestry Commission and DEFRA links. Sounds more like leaf miner than fungal. Advice seems to be to sweep up fallen leaves and destroy them (not composting).
Our 40 yr old Horse Chestnut has become very sick. The leaf cover is very sparse and yellowing. Today I noticed a thick growth of a blue-grey fungus, like tiny mushrooms clustering round the base of the tree and over the superficial roots. Please can you advise re. treatment.
The problems that are being discussed above are all treatable when caught in time. Bleeding Canker responds well to soil fertilisation treatments, Guignardia can be treated with fungicide sprays to the crown, and Leaf Miner damage can be controlled by introducing a systemic insectide into the tree. Trees can also undergo decompaction work and fertilisation to improve their growing conditions and hence health.
http://www.savethechestnut.com has further information.
Although not fatal, being defoliated for three months of the summer means an inevitable decline in the health of the tree. The result of this defoliation is that previously healthy trees capable of fighting off infections, are now far more susceptible to getting infections that will kill them.
Neil Smith
17 December, 2009