Yesterday I discovered cuckoo spit on my red valerian (Centranthus ruber). It’s considered a pest by many gardeners, but, for me, it’s a symbol of great achievement: I’ve successfully converted a barren, paved courtyard into a lush, green (albeit tiny) garden.

The garden isn’t perfect and I’ve a long way to go, but I’ve documented my success by the variety of garden visitors I’ve gained since the transformation: blue tits and great tits, bumblebees, butterflies, moths, slugs, snails and leaf miners (the last three new residents I’m less delighted about). And now the froghopper nymph, which is happily undergoing its own transformation in the safe cocoon of cuckoo spit on my valerian.

As a child I was fascinated by cuckoo spit. No-one explained what it was, so I’d look to the sky for answers, hoping I’d see a cuckoo swoop down and spit on the plants. It was only a few years ago that I learned about the froghopper nymph, which protects itself from predators and dehydration in a coating of froth, before emerging as an adult.

Froghopper adults are fascinating too. Apparently their colouring can vary according to their location, and it’s thought that urban froghoppers are darker than their cousins in the country.

If you can deal with the unsightly globules of ‘spit’ on your prized plants, leave them to get on with it. The nymphs and adults suck sap from plant stems, but in such small quantities they rarely cause leaf distortion. I don’t mind even if they do – I like them.