Please report this to the Secretary. Breaches of boundaries are taken very seriously.
Please be aware that you risk damaging the plumbing system if you dig or fork over the boundary of your plot; you could make your path more attractive to intruders if it does not have clear sight lines, and also risk damaging your relationship with your neighbours.
Tenants and their guests are not allowed to enter a plot without an invitation from the plot holder. You must not take anything from any plot, regardless of whether it appears to be neglected.
← 5.3 What can I do about my neighbours going over boundaries?