The Lord of the vineyard, also called the master of the vineyard, is the owner who labors to save his decaying olive tree in the allegory Jacob quotes from the prophet Zenos (Jacob 5). When his tame olive tree begins to decay, he prunes it, digs about it, and nourishes it so that it will put forth young and tender branches and not perish, doing so to preserve its roots unto himself (Jacob 5:4-5, 11).
He places natural branches in the nethermost part of the vineyard to preserve them and lay up their fruit against the season (Jacob 5:13). After wild branches are grafted into the tame tree, he looks and finds it bearing fruit like the natural fruit, and judges it good (Jacob 5:17-18). When corruption later spreads through the branches, he resolves to keep laboring rather than lose the trees of his vineyard, sparing it a little longer though it profits him nothing while it brings forth evil fruit (Jacob 5:29, 35, 51).
For the last pruning he calls servants to labor with their might, promising them joy in the fruit if they work with him (Jacob 5:62, 71). The natural fruit returns and the natural branches thrive while the wild branches are plucked off; seeing his fruit good and his vineyard no longer corrupt, he tells the servants he has preserved the natural fruit as it was in the beginning (Jacob 5:73, 75).