Cherry silverleaf

[Dan Maynard]

I have been asked to reduce a pair of cherry trees in a garden. Will be a light reduction, no cuts over 2".

 

All the books say not to do this now because of risk of silverleaf fungus, now it's been a really warm autumn so I think effectively summer is extending, my question is how big is the risk of silverleaf infecting the trees? Do I refuse the job till May?

 

I searched back through the forum but mostly found references to cherries and plums in orchards or growing for fruit.

[AJStrees]

Hi Dan, presuming the trees are for fruit and not flowering cherries? It is my understanding that stone fruits have to be pruned in summer months otherwise yes it could be deadly.

 

My tutor on a course I did some years ago for orchard tree pruning was pretty adamant that stone fruits should only be pruned in summer months. When I contacted him this year about pruning a cherry tree (mid june) he was very positive about the pruning being done in June and not over autumn/winter. 

 

Besides that I believe silver leaf is more abundant during autumn due to the damp days and the much larger amount of fungal spores that are air borne at this time of year. After all, this is pretty much fungi heaven at the moment so I would say not to prune at this time. 

 

But I am sure there are many more views and experience of such on here. 

 

 

 

 

[daveatdave]

plus 1 for A J post

[nepia]

plus 2 based on theoretical knowledge; not worth the risk of cutting it now I'd say

[sime42]

According to what I've read and heard the fungal spores that cause silver leaf spread in damp, humid air. Hence why it's not good to do it over winter. Better done between May and September, preferably during a hot dry spell.
I get what you mean about the extended summer but in this instance it might actually be the worst time to do it! Damp and unseasonably warm. I'd leave it until next year.

[Dan Maynard]

It's flowering rather than fruit, not sure if that makes much difference. Still feel it's difficult to quantify the risk, I guess we need to do loads of trees and count cases of silverleaf, but of course nobody wants to be in the experiment just in case.

[sime42]

I don't think it makes much difference, flowering or fruiting type cherry trees. They're very similar really just a question of taste! All Prunus are susceptible apparently.
It would be interesting to get an idea of the actual risk. I've no idea how likely or not it is that you would get silver leaf if you pruned at the wrong time. Surely if there were no other infected trees nearby then it should be ok. Unless the fungus has other host plant species.
You're meant to disinfect all tools before you start as well to prevent cross contamination .........

[slack ma girdle]

I have not seen silverleaf in Pembrokeshire for years, but in the last couple of years i have to remove about 10 which had succumbed.  Interestingly none of the dead trees had been pruned, and i suspect that the silver leaf was a secondary infection.

[daltontrees]

My ubnderstanding has always been that cherry 's main means of defence after breakages or abrasions (and so after pruning) is the production of gum which blocks the infection pathways. This is at its maximum production in summer months, therfore that is the best time to prune. However, I don't know how a tree knows when it is 'summer'. Some  tree species react to day length, some to air temperature. If cherries react to daylength then gum production will tail off even if autumn and early winter is mild. If so, pruning now would be risky.

Edited November 6, 2021 by daltontrees

[Paul in the woods]

I understood you prune cherries in summer not just because there's less spores about but also so the wounds heal quicker, or at least are covered over by the plants sap.

 

Having said that I don't understand why cherry plants sold in winter are freshly pruned. I also note apples are affected by Chondrostereum purpureum and they are pruned in winter.