As a committed organic gardener the use of persistent chemical poisons is anathema to me. I've discovered a few good alternatives, via the wonders of the World Wide Web, but I'm interested to know what works for others, particularly since it would be useful to discourage the ants which have begun to populate the garden since the rise in global warming. Note that I say discourage - I have no intention of obliterating these insects and indeed feel uncomfortable with killing anything unless absolutely necessary. Some recipes I've used seem to gum up the leaves of plants, affecting their growth, and I'd like to avoid these
For insects other than ants, aphids in particular, this recipe works well for me:
1 and 1/2 tsp Castile soap
1 and 1/2 tsp white vinegar
Made up to a gallon and applied via spray bottle, sparingly applied in the evenings to avoid direct sunlight.
For an extremely effective and non-toxic weedkiller, used last year by my allotment neighbour, and one I'm just about to trial myself for paths and hard-to-weed crevices.
1/2 a cup of Ecover washing up liquid, or similar.
2 cups Epsom salts
Made up to a gallon in white vinegar
The recipe doesn't say whether the ingredients should be added together or one at a time, so my intention is to dissolve each ingredient in half of the vinegar then blend the two. When Emma used it, it seemed to effortlessly knock down anything it touched, so care will be needed. I'll report back after using it. She hasn't been around for a while, so I've been unable to ask her how she made it up.
There are several other insecticides mentioned in the linked articles shown below; the tomato leaf one seems particularly interesting.
https://www.treehugger.com/natural-homemade-insecticides-save-your-garden-without-killing-earth-4858819https://verminkill.com/homemade-aphid-killers/#:~:text=A%20combination%20of%20vinegar%20and%20Castile%20soap%20is,main%20ingredients%20being%20mineral%20oil%20and%20olive%20oil.