This poem seems to echo that of a story of a married couple. The man is surrounded by beauty, and at least one beautiful woman, but he declines them all to return to his wife. He is very possessive with his constant use of the word "my", and thus "imprisons" his Rose Tree. She, however, turns away with jealousy and in turn only reveals her thorns to him.[2]
Johnson describes My Pretty Rose Tree as "...an ironic reconsideration of the emblem convention. Blake's speaker, having rejected the lovely flower offered him, tries to tend his pretty rose tree with all the single-minded ardor of a Petrarchan lover; but his devotion is a sickness nourished by his perverse or ironic 'delight' in the thorns of jealousy. His love object...both attracts and repels..." This echoes the idea of "Human Love" as we often want things we can't have, and become infatuated with things, or idealizing them instead of actually loving them. The rose tree showing her thorns of jealousy only entices the man more, much like it would any other human.
One theme continuously echoes through the minds of critics: Possessiveness.