How do you make your garlic insecticide? My gardener will insist on using slug pellets, no matter how often I tell him not to and that I am against their use, so maybe if I make garlic insecticide he can be persuaded to use that.
I simply chop up four or five whole garlic bulbs (skins and all) and if the slugs are being really bad I'll add one chopped bird's eye chili pepper as well. Depending on what herbs I have growing in the garden, I'll toss in a bit of anything I know they don't like- thyme and rosemary are both good.
Then I pour in a litre of water and put it on a slow boil for about 15 minutes (with a lid! because it really reeks.) If it's a sunny day, I stick it out in the sunshine when the smell indoors gets to be too much... I've discovered a hot pan sitting in direct sunlight will continue to steep quite well.
Then, I strain it into a large bottle and keep it in the fridge, and use it as needed in a spray bottle. I have to redo it after a rain, which is a nuisance, but I prefer that to slug pellets, too. What with having frogs and fox cubs in the garden, I just don't like have a poison sprinked around on the ground.
just wanted to add... it seems to deter aphids, too!