Many perennials maintain a visible presence in the border in winter (some asters, heucheras, etc.) but others die back and leave no trace (e.g. delphiniums and some hardy geraniums such as ‘Rozanne’, shown in photo). In case of memory lapses regarding my border layout, I regularly put in short bamboo canes in autumn to indicate the whereabouts of winter-invisibles. This can prevent trowelling disasters come springtime and help spot the tender sprouts to protect them before the slugs get at them. I use short canes dipped in green paint at one end so as to make them more visible and add to the garden decoration. More different colours might be used to differentiate between the plant species thus marked. I might do it in the future.
Text adapted from this Daily Telegraph article.