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A usually mild, sunny spell of weather in early autumn, often between mid-September and early October. It is marked by clear days, cool nights and delicate strands of gossamer drifting through the air – hence its old German name "Altweibersommer", derived from the Old High German "weiben" (to spin).

Inorganic fertiliser contains nutrients in inorganic, mineral form. These nutrients are already water-soluble and are usually available to plants very quickly after application. Inorganic fertilisers are manufactured industrially or obtained from natural mineral raw materials.

An insect hotel is an artificially created nesting and overwintering site for insects in the garden. More and more amateur gardeners are turning to this option to attract beneficial insects into their gardens and provide them with a permanent home, as a means of biological pest control.

Insects (Insecta) are the most species-rich class of animals, with well over a million known species. The name comes from Latin, derived from in-secare, meaning "to cut into", which actually translates as "cut-up (creature)" and refers to the clearly separated body segments.

An invasive species is a non-native plant, animal or other species whose spread can threaten biodiversity.