The Heartleaf Philodendron is known as the sweetheart plant because of the unique heart shape of its leaves. This ease to care for plant is one of the most popular houseplants. The Heartleaf Philodendron is an evergreen vine that thrives in partial shade at moderate temperatures. In tropical regions it can survive outside, however in most places it is used strictly as a houseplant. While blooms on this fast-growing climber may appear at any time during the year most plants in confinement never bloom.