Canker on small Cherry blossom tree

[deeahgwitch]

Unfortunately a small cherry blossom tree I planted about 4 years ago has canker (I think but am almost certain it is canker).
Apparently you have to prune the parts that are affected in July or August but obviously it's too late now.☹️
Anyone experienced the same and if so what did you do ?
There is no fungicide available to the amateur gardener.

There is fungicide available to the amateur gardener in the UK (Roseclear do one for instance), but what I suggest you use is 'winter wash' which is available in garden centres. It will at least help to prevent the spread of it until you can prune it at the right time of year.

Canker on Prunus is usually bacterial so fungicide wouldn't help anyway.

Thank you both for advice 💐