When I was  child my mother used to worship BARGAD  i.e. Ficus bengalensis and  PEEPAL  i.e.   Ficus religiosa on a particular day in month of June calling Badmawas i.e. dark moon day falling in summer. BOTH THE TREES HAVE LIVES OF OVER SEVERAL HUNDRED YEARS.
We have to find a tree to worship it The idea was to grow this tree which will protect the people.
It was sin to cut the twigs of Ficus religiosa. 
A festival in winter time was to worship AMLA i.e Phyllanthus emblica  
Lord Shiva has to be worshiped with leaves of Belpatra Balanites aegyptiaca. and Datura stramonium fruits, and Calotropis procera flowers besides others.
Every Hindu house must have a Tulsi i.e. Ocimum sanctum and worship the same. No doubt India has less dengu feaver in olden times because Ocimum sanctum has mosquito repllent capacity besides having radioprotectant and anticancer activities. Hindu temples give water mixed with Tulsi.
Japan has several trees associated with its religious places and dwellings. Moghul emperors  are known for their love for Mangoes Mangifera indica.
Every culture has some religions which lay importance on trees. Christmas tree is famous example.
Its important to rekindle the love for plants from the people having declining inclination towards religion and religous ceremonies as practiced by our parents.
Global practices based on religion and plants together could be illuminating excersise and enthuse the people to return to plants if not religion.