Hi,
I live in Portsmouth (UK). Since this Spring, I have begun noticing the condition of the trees in the area. At first, I focused on the horse chestnuts which, as we all know, are suffering greatly (I'd say catastrophically) from the leaf miner beetles. I know a guy who has for a little while been pretty alarmist about them, saying they'll be completely gone from our countryside inside two decades. I didn't agree with him at first but now I would go further; they're in a terrible way, even the trees with zero visible infestation - featuring simply scorched leaves and die-back. Old, young, it makes no difference.
The next species that drew my attention is the cherry - principally the blossom trees planted by gardeners and councils but cherries in general. I saw that the ones I passed regularly were showing defoliation (in June), die-back, leaf-scorch, but also horrific damage to the bark, and weeping resin. I have made a point of investigating hundreds of these trees, when I can (though I have seen thousands) and they all show the same symptoms. Looking up the symptoms, this is gummosis, with the advice being to remove the infected tree from the environment. Well, this presents a certain issue seeing as just about 99% of the trees I see are thus afflicted. The damage, to be clear here, is eye-watering: in many instances the bark has just peeled off and lifted right away from the heartwood, to the extent that it is obvious the tree will soon be dead. Amazingly, many of these trees are yet in reasonable leaf - though I now note the decline of local individuals on a weekly basis - causing me to wonder how recently the damage has occurred. The extent of this is so bad that I came here expecting to see a lot of discussion about this. I will be amazed if any of these cherries are still around two years from now.
It gets worse, however. The more I have learned to recognise defoliation, crown die-back and the various pathologies unique to each species, the more I see it. Go into any residential street in Portsmouth and you will see rowans with half the branches completely dead, sycamores displaying die-back, purple-leafed plums horribly defoliating, hazels with dead branches. Any road. I've surveyed a few roads near my workplace for the damages particular to each tree - I would conclude that about 80% have something seriously wrong with them, the majority displaying horrible bark damage near to the base. These are verge trees, however, for the most part, so I suppose it could be reasoned that they aren't in an optimum location, even though some have been there at least thirty years or more. (It is true that the more asphalt surrounds the tree, the worse they appear - the alders around the nearby Sainsbury's all look like they've been hit by lightning).
So I have also surveyed local parks and recreation grounds. If anything, the situation is worse. Some dead trees here and there, some half-dead (with that reduction in crown where the leaves appear to demarcate a smaller tree within the halo of dead branches), but when I walk among the trees I find that 90% show serious bark damage just above ground level, also with a kind of lateral eating away of the bark - through cambium and xylem layers to the heartwood. I take photos and am not selective because I don't have to be. This is alders, poplars, ash and aspen, and some absolutely massive weeping willows where the bark of the tree looks like someone took a blowtorch to a candle. There are two Eastern black walnuts with some minor leaf loss but nothing very worrying, unlike the English walnuts, which are starting to look quite ill.
I noticed when I am in Fareham that the plane trees all along the town centre have stunted and twisted leaves. There is a large-leafed tree (I think it's a foxglove tree) at the end of the pedestrianised area which is showing severe die-back.
There's an avenue in Portchester (Birdwood Grove FWIW) with a shaded walk down to the sea which is planted with (sweet) chestnut trees. There's been an amazing harvest there every year and the trees look fine - until you inspect the trunks (through the nettles) and find that every single one has that blowtorched candle effect.
I'm watching all the lime (tilia) trees in my neighbourhood. Some are fine, though I can't access the trunks (either because they're sprouting like crazy from the base or because they're behind hedges), but others are displaying die-back. Oaks, too. I passed a grand old pedunculate today which had been chopped in half; the remaining leaves were pretty pathetic and it was obvious the tree will be dead soon. I stopped my car, jumped out and assessed the trunk: mounds of particulated wood from insect infestation, black sap running down the trunk, and two large sections above the roots where there was only dead wood on display, no bark. On its own, this is simply a dying tree. But taken alongside everything else, it seems like trees en masse have lost immune function. If there's a pest or a disease that can attack a tree, it's just party time.
I've phoned tree surgeons and they seem oblivious, unaware even of the plight of cherries (which is amazing to me). I've spoken to park wardens, tree wardens - they know of a disease afflicting a particular tree, but then they simply shrug.
It makes me wonder about all the piptopori I was picking from birches last year. I now suspect their immune systems were compromised because these were harvested from standing as well as fallen trees.
Can anyone verify, dismiss, or explain what I'm seeing?
I have several one- and two-year-olds in pots (I had collected nuts and left them outside in a basket - the radicles sprouted in late November so I put them into soil), and they seem to grow leaves in a haphazard, inconsistent way - and later than everything else.
