Tropical plants with big leaves add drama to tropical landscapes and botanical gardens, but many big-leaved plants are trees that grow well beyond the scale of northern gardeners who want a focal plant for a sun porch or corner garden. Other trees or lower-growing plants, many from the arum family, offer exotic accents for "interiorscapes." Like all tropical plants, big-leaved plants require additional humidity during heating season to maintain healthy foliage.
Two fig varieties, members of the Moraceae family, grow only as large indoors as pot size allows. Ficus elastic or rubber trees have thick, glossy oval leaves that grow up to a foot long, some with red edges or highlights. Ficus lyrata, the fiddle-leaf fig, has longer, wavy, violin-shaped leaves and a reddish-brown trunk. Its leaves are thin, but grow a few inches longer than rubber tree leaves. Although the rubber tree's fruit is very small, both trees bear figs in spring with enough light. Both prefer medium light levels; they grow in full sun to partial shade in the wild. Fiddle-leaf figs must be kept evenly moist, but the rugged rubber plant, a favourite office plant, will tolerate drying between watering.
The cast-iron plant gets its common name for its ability to tolerate neglect. It prefers low light levels -- medium to deep shade in the wild -- and tolerates drought and a wide variety of soil types. Aspidistra elatior is a slow-growing ground cover in the wild, growing in clumps from rhizomes, making it an easy plant to propagate. Oblong leaves grow 18 to 30 inches long and may be green or variegated. Aspidistras are more hardy than many tropical houseplants and can grow outdoors along the coast from Virginia, around the South, and up the Pacific coast to Seattle.
Several arum family plants share common names. Alocasia species, Xanthosoma sagittifolium and Colocasia esculenta are all sold under the name, Elephant Ears. All are upright, showy plants, growing from tubers. X. sagittifolium leaves resemble oblong shields up to 36 inches long; they may have scalloped or ruffled edges and are soft green or variegated. Varieties of this elephant ear can grow to 10 feet tall and wide. C. esculenta bears arrowhead-shaped, soft bluish-green leaves that grow up to 24 inches long on 3- to 6-foot clumps. Both elephant ear plant varieties require evenly moist soil and are medium light plants. Outdoor cultivars adapt well to wetland environments.
Other big-leaved arums have split-lobed leaves. Cut-leaf philodendron, or Philodendron bipinnatifidum, bears deeply lobed, wavy-edged leaves with an overall heart shape that can grow 3 feet long. P. bipinnatifidum trees can grow 15 feet tall and wide. The Swiss cheese plant is often called "split-leaf philodendron" but is actually Mostera deliciosa, a close relative. The rainforest vine grows to 70 feet, with huge flat leaves that may have holes as well as slits; it tolerates low light. Both plants tolerate dry soil, but their leaves burn in direct sunlight. Like other smooth-leaved tropical plants, they should be misted when winter humidity drops.