Butterflies and caterpillars need more than a friendly plant or two in the garden, and just like us humans, they also have certain preferences. In the case of butterflies, they like a spiral or three-dimensional garden bed with a variety of larval host plants. Such a bed is the ideal habitat for insects, according to the German Nature and Biodiversity Conservation Union (NABU). A spiral bed winds its way upwards similar to an herb spiral, which becomes narrower towards the top and is bordered by large stones. The site should have room for a bed at least three metres in diameter, with the lower…