Plum Tree Dying - Please Help

chris.weeks

Good Morning all,

i have a major and ongoing issue with my established plum tree - it was in the garden already when i moved in a few years ago.

Every year, it has not produced any unspoilt fruit and at the fruit development time, the leaves/blossom begins to die and the small fruit just elongates and shrivels up.

i dont know whether the tree can be saved or not or what it is?

i have attached pictures, with the last one being a close up of the spoiled new fruit.

can anyone advise me please on what it is and what can be done?

thanks in advance!!

BobTheGardener

'Elongated fruit' sounds like 'pocket plum' disease:

https://www.rhs.org.uk/advice/profile?pid=199

All you can do is prune-out all affected material.

chris.weeks

Hey Bob, 

yes i did see that through my research before posting but it didnt explain the blossom and leaf die back on the pics. Not sure whether im dealing with a few things at once. It has been going on for a few seasons so not sure whether its now inside the tree itself 

BobTheGardener

Hi Chris, it could well be more than one thing - possibly silver leaf or even fire blight.  None of the potential diseases are treatable with chemicals and pruning back to unaffected wood is your only recourse.  Try cutting through some of the most affected branches and inspect the wood.  Any coloured (usually brown/black) staining indicates a disease and you need to keep cutting back until the wood is clean and white.  Use a bleach solution to wipe your secateurs between each cut to prevent spreading it further.

If you find any staining of the heartwood, please posts photos as they should help.

chris.weeks

Thanks very much Bob, really appreciate it and will post photos. I dont suppose it would do much further harm to prune at this time of the year would it? 

BobTheGardener

Although it's less than ideal to prune stone fruit until mid-summer, in this case I would say it's more important to halt the spread of any infection.  Wet, cold conditions are the things to avoid and the short-term forecast is dry & warm so I would take the plunge now.

chris.weeks

Hi Bob, hope you’re enjoying your weekend. I managed to get out and start cutting down the above plum tree branches. As soon as i got close enough i noticed sap coming out. Ive also took a picture of the inside closest to where the dying branches are and there seems to be dome discolouring - it doesnt seem bad when you cut closer to the trunk. Ive attached some further pics and would appreciate your thoughts? Thanks in advance 

BobTheGardener

Hi Chris, to me it looks like Fire blight, unfortunately.  Have a look here:

https://gardening.which.co.uk/hc/en-gb/articles/115001752629-Fireblight

and here (note that the RHS says it doesn't affect plums but most other sites say it does!):

https://www.rhs.org.uk/advice/profile?pid=160

There are also bacterial cankers which look similar.

Either way, I think you need to sharpen those secateurs and keep cutting back until the layer beneath the bark is clean and white.

chris.weeks

Thanks Bob, doesnt sound great! Ive read the articles and its as you said originally i think, to prune it down below the rot. It talks about cankers being the ‘sunken areas’ of the branches and there is a fairly big area like that on the trunk itself, so not holding much hope!

Thanks for your help