A secret garden is within the mind that is controlled by ego until ego becomes secondary in ones evolution. The secret garden that is spoke of in so many songs is the oneness of being your true self with no words. Words are learned, manufactured and filtered by the ego. Everything is labelled to each individual as good, bad, or irrelevant. It is the used over and over again until one realizes their own conditioning or programming from ones experience and past.
The ego is there to protect and survive, it knows nothing else until the awakening happens. The process of awakening to reality is a garden in itself. There are really so many possibilities for every outcome that if an ego is re-trained, or repent, then consciousness can expand and evolve into what humanity can really be.
The secret garden for me is the meditation of the mind to just be in Alpha consciousness. This is where the creation happens. This is where we can just be with our own non egoic thoughts. This is where you can download what is. Science is ego’s label for what is.