The top two figures have tree crown significance.
The bottom two figures have tree root system significance.
The north-east figure has a rising sun connotation.
The north-west figure has a setting sun connotation.
There is also a butterfly image which is a good association for wild life tree gardening.
From a plan perspective –
The four figures represent the four seasons, starting south-west for winter – moving north-west for spring – across to north-east for summer and then down to south-east for autumn. In addition each of these figures (leaves) vary according to the seasons.
The logo can also be seen from a helicopter perspective as a spreading tree crown.
From the same view it could also be seen as the root system radiating outwards.
It would also be seen as the sun with its ray spreading 360 degrees.
In terms of our strap-line (compound last joy) the figures enlarge in a compound fashion.
Diametrically one could also construe the NW — SE axis as a tree crown with its trunk and likewise the NE — SW.