Landscaping with Poinsettias

This is a picture of a house and the front yard of a house I saw in Kona on Hawaii. It was December, But I was completely stunned by this. As specimens of poinsettias, they were ancient and grand. The youngest had trunks as thick as my upper arm. The oldest had trunks as thick as my fat thighs. They seemed to have been maintained by pruning.While this is a unique take on landscaping, not everyone would want lines of Poinsettias in their yard.The younger ones seemed to be at the bottom of the slope and I wondered if the landscaping represented years of Christmas Poinsettias that had been planted out.
Poinsettias were growing in many people's yards (although this certainly takes the cake as far as abundance), but they also seemed to have escaped and were growing "wild" in places beside the road. It is easy to see how completely innocuous plants could become a menace in place where there is no frost.