How do I safely get rid of ants on my William Pear Tree

Just a note to express sympathy - what a disturbing thing to happen! I don't know anything about pear trees, but others will

Are the ants chasing something else? Does the pear tree have aphids - they could attract the ants and also make the leaves curl up? Uncurl some leaves and have a look.

The ants are going up the tree to feed on aphids or something else which may be on it .The ants will not harm the ttee but there must be something attracting them . Inspect thoroughly and I assume it is only a small tree so wash it over with some tepid soapy water leaves braches etc. I am sure the tree will be O.K. eventually don't despair!!!

Agree 100% with Wyeboy. UK Ants are totally harmless to plants above ground - we don't have soldier ants so your ants will not harm your pear tree. As Wyeboy says the ants are being attracted by an insect food source which is causing the leaves to curl up. Lookinside the curled leaves and you will find the culprit(s). If you are not keen on using proprietry insecticides do as Wyeboy says use luke warm soapy water - I would apply it via a 1 litre hand held sprayer and thoroughly wet all the leaves, repeat again after 24 hours. Best of luck

If you do decide you need to get rid of ants i have found ant traps worked really well. just put one near ants keep pets and kids away ants will be all gone in 24 hours. I only did it because they were marching across my kitchen table and into all our food. I try to leave nature alone generally.