Love is altruism, giving oneself away. True Love can not be egocentric. Love as compassion, tenderness, patience, readiness for self-sacrifice and so forth is the basis of ethics. And ethical component is the foundation, pivot of the growing spiritual person. Not only spiritual leaders can help us learn to love, not only other people but simple plants as well if we would like to study.
Plants are live, feeling beings, capable even of emotional reacting.
Plants are, as we are, physical bodies with incarnated units of life in them. This is the way to treat plants if we want to learn love. Plants are living beings. And we can learn to love any such being unfolding capacity of emotional love in ourselves. The more objects each of us has learnt to love the wider, more perfect is our love.