Advice on a diseased plum tree.

Bumping this

Plum trees are susceptible to a number of fungal infections. I can see signs on your daughter's tree which might be silverleaf and/or brown rot - but there could be others too.

Fungal infections get in through a wound in the tree...but this can be as simple as the damage caused by a bird pecking at the fruit.

If it were my tree I would take all the fruit off and prune out the worst diseased branches. The time to prune is in summer for a plum tree. Remove all the removed parts from the site or burn them. The removal is important as rotten wood and/or fruit sitting around will enable the fungus to pass back to the tree. Fruit rotting around the tree in autumn is a route to reinfection.

Then I'd look after the tree like fury. If it's in a lawn, remove the grass from the area around it, weed around the tree (to remove competition),and apply a thick mulch of compost and bark. Water thoroughly and often. Then wait and see what happens next year. In a year or two things might improve. If not repeat all the above. If things don't improve then you would have tried your best and it might be time to remove the tree.

I'm a gardener not a tree expert, so if someone comes along with better knowledge I'll be all ears.

If no-one responds to this I think that google might be your friend. There's sure to be pages about disease in plum trees.

Does your daughter have any sort of horticultural training establishment nearby who she could contact? They would probably be able to advise.

I agree with RichmondPark .
First class knowledge !

What a shame -it looks like a nice fruiting tree .
Plum trees are susceptible to many nasties and I can't tell from the photographs what it is .

I'd add using Provanto as an anti fungal treatment .
We used to use a winter wash on fruit trees in November . It cleans them up nicely freeing them from bugs for the next rowing season .
You can use it up until February .

If your daughter isn't able to nurse the tree back to health -because she's too busy / has children and pets and isn't keen on chemicals - no criticism - it might be better to remove it and replace it with another choice of tree -not forgetting that viruses can live in the soil .

Good luck .

Thank you all for your help.My daughter is keen to keep the tree.

When I was first newly married our house had an orchard with apple, plum and pear trees. My husband used to use a wi ter wash to control infections and pests. ink{https://www.gardenersworld.com/how-to/grow-plants/how-to-winter-wash-trees/www.gardenersworld.com/how-to/grow-plants/how-to-winter-wash-trees/ THIS article} explains how to do it.

I never use winter wash on fruit trees just because I try to garden as naturally (cheaply) as possible and avoid using anything that might interfere with the balance of the system. I have found that leaving the 'wildlife' to it means that something will soon come along and eat the thing causing the problem and I don't want to interfere with that cycle. I worry washes and chemicals will kill beneficial insects, moths, butterflies etc.

Organic winter washes are definitely available though if you want to go down that route.

I don't either , but these were commercially grown trees . The plums were sold for jam making .

When it comes to economics I don't think that most farmers think about wildlife - at least they didn't use to !