Pocket Plum

Lindsay Fisher writes: Maggie C’s recent post about alder tongue galls reminded me of a curious disease that ruined our damson crop this year. Suddenly the apparently normal young fruits exploded into grotesque elongated shapes, turning pale and withering without forming stones.

I’d never seen anything like it, but it was easy to identify from the RHS website. Pocket Plum is caused by a fungus called Taphrina pruni – obviously a relative of the alder tongue gall (Taphrina alni). It is believed to be associated with the leaf-curl fungal disease often seen on fruit trees in the plum family (our trees also develop this most years). It also affects blackthorn (sloes) and you might see something like it in the hedgerows.

Alas, there’s no cure, and the only way to control it is to chop off and destroy all the affected material. The pheromone trap I set up to catch plum maggot moths has proved rather a waste of money. Luckily I still have some damsons in the freezer from previous years, but there won’t be many to harvest this time. 

Lindsay Fisher 10 August 2023