A dozen red roses has long been a mainstay of Valentine's Day. While fresh flowers soon wither and die, a houseplant can be a long-lasting expression of affection. Houseplants with heart-shaped leaves, including a Valentine's Day decoration, can be just the right gift for a special person (Figure 1).
Heart leaf philodendron (Philodendron hederaceum), golden pothos (Epipremnum aureum), and sweetheart hoya (Hoya kerrii) are easy to grow indoor plants with heart-shaped leaves. Heart leaf philodendron has glossy, dark green leaves on twining stems that will trail or climb when trained and tied to a support (Figure 2). Philodendrons thrive in indirect light in a highly organic, soilless potting medium that is kept barely moist. Plants can be fed with a general-purpose indoor plant fertilizer every three to four months. The terminal portion of stems are pinched when a shorter, fuller plant is desired.
Golden pothos, also known as devil's ivy, is another vining plant with variegated, heart-shaped foliage that can be trained to a support or grown in a hanging container with trailing stems. Golden pothos plants prefer bright indirect light and the potting medium can become moderately dry between watering. Like philodendron, golden pothos will thrive with fertilization every three months and maintained as compact plants by pinching stems.
Sweetheart hoya is one of the many species known as wax plants. Sweetheart hoya is a vine with fleshy dark green, heart-shaped leaves. There are also selections of sweetheart hoya plants with white bordered leaves. With a bit of tender loving care, plants produce an interesting umbellate inflorescence in the summer. Umbels are up to one inch in diameter. Each of the small flowers has a dark red, daisy-like corona surrounded by the white corolla and is scented (Figure 4). Although sweetheart hoya is a durable plant, grow it at a temperature above 59°F. Plants require light for flowering but no more than two hours of bright sunlight per day. During the winter, hoya can be watered as little as once per month and is sensitive to overwatering and overfertilizing. Apply a fertilizer product labeled for succulents and cacti no more often than once a month, with one application when flowers begin to develop.
String of hearts (Ceropegia linearis), also known as sweetheart vine or rosary vine, has green leaves highlighted with white veins that resemble small hearts on cascading purplish stems. C. woodii f. variegata is another type of string of hearts that has white and pink variegated foliage. These succulent plants also develop interesting fountain-like flowers about an inch-long, generally in the summer or fall. Flowers have a bulbous base a with a tubular, pale magenta corolla. Petals are fused at the tips, forming a dark purple, crown-like structure. Plants are best grown in a south or west-facing window at temperatures above 60°F. Maintain string of hearts in a well-drained potting medium labeled for cacti or succulent plants and allow the medium to dry before watering. Like other succulents, string of hearts requires infrequent fertilizing.
Heart fern (Hemionitis arifolia) or tongue fern has dark green fronds that are typically about two inches-long. At maturity, heart ferns on reach six to eight inches-tall. Since this fern is an epiphyte and typically found in tropical forests, it is best grown in a terrarium or in a humid environment with bright, indirect light at temperatures between 60 and 80°F. Keep the well-drained potting medium moist, but not wet and fertilize monthly with an indoor plant fertilizer diluted by fifty percent.
Cyclamen plants not only have heart-shaped leaves, but also produce showy flowers in a multitude of colors. Cyclamen flowers will persist for several months when kept in bright light and about 70°F during the day and 50 to 60°F at night. Uniform watering during flowering to keep the potting medium moist, but not saturated, is also critical to prevent flower wilting.
After flowering, with a bit of effort, the plant can be forced into bloom once again after a period of rest. After flowering, gradually withhold water until the foliage dies back. Do not water the cyclamen for six to eight weeks. After this time, begin watering the plant gradually and repot if needed. Place the plant in a lightly shaded cool area outdoors or near a cool, shaded window indoors. When new leaves begin to develop, resume normal watering and fertilize using an indoor plant product, and relocate the plant to a sunny location to encourage reblooming by midwinter.
Anthurium is a showy Valentine's Day plant with its large, captivating flowers consisting of a spathe (shield-like bract) that bears a central spadix. There are several species available for planting, but Anthurium andrenum develops vivid red spathes that are about four to six inches-wide. Anthurium plants produce flowers continuously, with each one lasting about six weeks. Plants thrive in bright indirect light, day temperatures above 68 and 85°F, and 60 to 65°F night temperatures. Water plants thoroughly but allow the potting medium to dry slightly between watering. Fertilize plants sparingly, about once a month. Because Anthurium plants are poisonous, keep them out of reach of small children and pets.
Embrace Valentine's Day by sharing your love of plants with a special person.