We have an ant problem on our allotments – I wonder if they are particularly partial to a silty or alkaline soil? Does anyone know? One of my allotment neighbours has found that if you disturb the soil a few times they move on.
I’ve tried it myself in the greenhouse and another patch outside and, so far, so good. Some plant roots will withstand the acid that ants release but I have found that cucurbits, potatoes and French beans are damaged quickly.