Left to its own devices, almost any patch of ground will not remain bare for long, before being colonised by some kind of plant. Even rocky shorelines are home to thrift and sea kale, and retreating glaciers are swiftly replaced by alpine grasses and willowherbs.
This planet may be small and blue by virtue of being seventy percent ocean, but the land is most definitely green.
Wild flowers are one thing, happy to be left to their own devices to grow, fruit and senesce. Gardening is quite another. Growing flowers and vegetables from seed is an art and domesticated plants are like pets—they need far more care and protection than their feral counterparts.
No one would call me green-fingered and plants in my care are rather taking their chances. Best intentions are soon forgotten and, before too long, a once well-tended patch is abandoned to the wild, as much as I am myself.