This is a post about diseases in a young plantation, so may be of most interest to those engaged in regenerating woodland.
As well as the patch of woodland (all conifers) I bought recently, 12 years ago I used a FC grant to plant 1-1/2 acres of native trees on the land around my house (in S W Wales) which had been sheep pasture.
About 5 years ago I noticed a problem among some hazel; a premature yellowing of the leaves and little new growth, followed in the succeeding years by limp, tired-looking leaves, no new growth, and die-back along the branches. This is disease #1.
Just recently I've discovered disease #2 which attacks the bark mostly of trees in the maple family (I have sycamore, norway maple and field maple) though I have also found it on an ash. The outer bark peels off in narrow strips, whereon the inner layers continually retreat, exposing the heartwood. This can quite quickly ring-bark branches or the whole trunk.
Disease #1
It's my *belief* that disease #1 is bacterial, passed from tree to tree by leaf-feeding insects. I say this because what I see is most closely matched by descriptions of fireblight, though it isn't that. How badly a tree is affected seems to depend on how easily it surrenders its leaves. The greatest number of casualties have been among hazel and silver birch, which hold onto their leaves and thus allow the multiplying bacteria to get into the ciculatory system, gradually choking it off. Almost every type of shrub seems susceptible, as are apples, but apples drop their leaves easily so whatever it is doesn't appear to trouble them unduly. However, even trees which are not seriously affected act as hosts for the spread to others.
I sent leaf samples to the Tree Advice Trust for analysis but they couldn't find anything. Nonetheless, I have trees and shrubs dying. I would like to have someone professional and knowledgeable come and inspect --but here's the problem: there's no way (on half a state pension) I can afford up to £90/hour for a site visit, so I've been struggling on alone. I'm posting this to the SWOG forum partly just as a heads-up for other growers, partly to see if anyone else has encountered anything similar.
These particular trees are planted quite densely, about 1200/hectare, which may well be exacerbating things. So, too, has been the series of excessively wet and humid summers we've had in the Western UK for the last few years. Also, I can't rule out a soil factor. This last winter I gave the most susceptible plants a fairly heavy application of lime and that does seem to have helped them fend off the problem a bit more readily than was the case last year --but now there's disease #2!
Disease #2
On the same speculative basis as above, I suspect disease #2 is fungal. I've trimmed back the bark around the affected areas and found no kind of beetle or other animal, unless they're microscopic. This summer has been so wet that there's hardly any tree that doesn't have some sort of leaf fungus on it. Where I can reach I've been trimming back the edges and painting with a disinfectant, but there's plenty more where I can't reach. I can see I'm going to lose more trees.
Actions
Apart from trying the lime, I've been thinning and pruning off all branches up to a height of 5 or 6 feet to increase air flow. I've also been much firmer in cutting out instances of disease #1 where I see and can reach it. The FC specified various shrubs to form an edge, but these grow so densely that they've formed a solid curtain, restricting the flow of air through the plantation. This is situated in a corner between two established farmland hedges/windbreaks, making it really quite sheltered. I feel that I'm fighting a losing battle, though, considering the way the climate is going.
I'd be interested to know if anyone else here has encountered similar problems, and what they've been able to do about it. Given that we're hearing so much about new and imported tree diseases, such as the recently identified ash die-back, and the emphasis put on increased tree plantation, I'd have thought the environmental institutions would want to know all about these kinds of outbreaks, but it seems difficult for the non-professional individual to raise interest. Small woodland owners may well have to rely on each other for advice and information. I can post images if this would be felt to be useful.
Brian Mitchell
