What does the line “he plants, in sap and leaf and wood” mean?

Here “sap and leaf and wood” refers to every cell of a tree. The poet wants to say that the tree planter’s loyalty and love for this big worldly home, his far-reached thought of civic good and his blessings on his neighbourhood are felt or reflected in the sap and leaf and wood of the tree — in every cell of the tree which he plants.

He plants in sap and leaf and wood,
In love of home and loyalty
And far-cast thought of civic good—
His blessings on the neighbourhood,

By the line he plants in sap and leaf and wood the poet says that the one who plants a tree loves the universe and very much concerned about it so he plants a tree so that human beings can get food from the sap and leaves and therefore he is referred to as god-like.