Q.Gerbera flowers are turning green
What causes this? My 18 year old plant has produced two green blooms instead of pinky orange.
When gerbera flowers turn green it means they have a viral disease and must be dug up and destroyed as it can spread to other plants. There is no cure.
Gerbera Daisy don't change color but often a different colored plant was potted together and will suddenly make a blooming appearance and through off a gardener.
It is unusual for it to take this 18 years to show itself, but not unheard of.
Congratulations on this long lived plant.
https://www.gardeningknowhow.com/ornamental/flowers/gerbera-daisy/growing-gerbera-daisies.htm