I have several trees in my backyard, but I have detected that specifically under the mulching of two trees (an avocado and a lychee), there are thousands of ants.
Every time I water those trees, they start to move everywhere, including climbing the tree.
What can I do to deal with them in a natural way? [ snip ]
The boric acid powder + sugar or syrup made into a thick paste that someone suggested earlier could work but you'd need a lot of it with that many ants. (This concoction works n cockroaches, too, BTW...)
Ants hate tansy (
Tanacetum vulgare = common tansy) so you could plant some of that around the base of the affected trees as an ant repellent.
A couple years ago I had a severe pest ant species (
Pheidole megacephala = big-headed ant = BHA) in my yard in Tampa that just walked thru any pesticides that I treated the area with. Nothing affected them and they were farming aphids and scales on my fruit trees. Finally in frustration I tried broadcasting Imidacloprid around the affected trees and watering it in well. This worked on the scales and aphids, killing them and preventing them from reproducing. This caused the BHAs to move away to farm untreated plants/trees in my yard. So I treated those trees with Imidacloprid, too, and the ants left those alone, as well. Eventually the BHAs gave up and moved out of my yard.
One of these ideas may be an option for you try to curb your ant infestation.
Good Luck!
Paul M.
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