Minimize agricultural pollution in your garden, on your balcony or on your farm – go organic. Do not use any pesticides. If your plants wither buy plants that are more robust or more suited to your climate. Do not try to keep plants that only flourish with chemical additives. Buy old varieties that can defend themselves. Pesticides have led to a massive die off of insects and birds in Europe.
Many species are still there in one corner or another but the numbers of insects and insect-dependent birds have plummeted to an all-time low. Nowadays you can see buddleias without a single butterfly. Nowadays you can walk through a patch of wild carrots and instead of 10 insects on every flower you will find one insect on every 30th flower. The web of life is becoming thinner every year.