A spot bordering the koi pond patio was perfect for the rambunctious cypress spurge (Euphorbia cyparissias, below), or so I thought. A granite boulder and a well established sedge hemmed the potential invader from one side, the stone patio to the other.

As occasionally happens, I overlooked a seedling of the dark leafed, native geranium (Geranium maculatum ‘Espresso’) that established at the far edge of the vigorous spurge. As the geranium grew to occupy a corner of the planting area I was pleased at first by the contrast of the spurge’s acid yellow flowers and the geranium’s foliage, and after flowering by the contrasting foliage textures. A happy accident, I thought.

But the geranium continued to expand its territory, little by little, until the last tiny clump of cypress spurge had to be rescued to transplant between boulders nearer the pond. Here, it slowly spreads, though I am watchful to remove geranium seedlings before they bully the supposed thug into submission.

There are lessons to be learned here, somewhere. Perhaps the spurge is not such a thug, or the native geranium is a bigger one. In any case, I’m pleased the spurge was rescued and usually happy to see seedlings of ‘Espresso’. I’ve weeded out dozens of its seedlings but saved many. The garden bordering the koi pond patio is better for the happy accident that played out between two bullies.