Oleander is a native plant of Crete and is very commonly found in watercourses, even when no water is flowing. The flowers in the wild are pink.
Oleander flowers from April to July with its peak around June. This is the time where gorges will fill with pink and dried water courses on hill sides bloom.
Oleander has also been cultivated for centuries and a wide range of colours and shapes can now be found and grown in gardens and alongside roads. With irrigation their flowering period is even longer.
Being highly poisonous goats pose no threat to them and they have become the flower of choice to plant along the National Road that runs along the North coast if Crete: it is beautiful, hardy and requires no maintenance other that occasional irrigation. The rather large bushes that it forms are also an effective sound barrier.
I was looking through part of Google Earth images to see if I could find a satellite view of Cretan roads lined up with oleander. Unfortunately in my neck of the woods the satellite imagery used at the moment was taken in January so no oleander flowers. I didn’t want to spend hours searching for summer images but if you find an area in Google Earth where long lines of flowering oleander are visible along roads please let me know where they are and I’ll add it to this post.