This conversation is important! There is a very good guideline to gardening: DO NO HARM! I don't believe, that we as private gardeners, not depending financially from our gardening product, have any right to put any toxic substances out in the nature. With the ecological problems worldwide we just cannot afford to do that. The only rational thing is to support the local ecosystem and garden as naturally as possible. One can weed by hand, remove aphids, slugs etc. by hand. There are plenty of good non-toxic methods against pests: water, oil, soap, baking soda, milk, garlic, partner planting, cleaning out the debris, using clean mulch etc. I think we should not cling to any sick plants and try to save them with toxic substances. We should exchange more about the methods, which really work.