In the performing arts a group of individuals can imitate something they never can do on their own. Think of the shadow dancers who are able to bring the illusion of being an elephant or a plane, just with their cooperating bodies.
People can manipulate the form of trees. They can plant them in certain patterns, but controlling the speed of their growth is getting quite difficult. The choreography of the above trees needs a planting scheme ranged over several years.
But, maybe the house was abandoned, long before the trees appeared. Maybe they have appeared, on their very own. And are imitating.