Livin’ Large

Much to the interiorscaper’s delight, many new shopping centers, offices and homes are designed with spaces specifically for plants. Designs take into account plants’ environment needs – adequate natural or artificial light, good drainage, access to water and proper ventilation, just to name a few.

Despite such improvements, maintaining attractive, healthy live plants indoors is still a challenge. This is because there is no such thing in the ecosystem as a “houseplant.”

The desire to incorporate a part of nature into our working and living quarters comes with some unique problems. Every building, site, exposure – even individual taste – impacts the potential for success or failure when setting up interior plant ecosystems.

Luckily, what has evolved over the years, in addition to improved living conditions for interior plants, is a selection of plants, tropical or desert in origin, which can tolerate an indoor environment. What follows is a selection of plants that will grow large or tree-like in our interiors and some recommendations for care. Because adequate light is so critical to the success of interior plants, these plants are divided into categories of: low light, medium light, high light and very high light.

In the first of this two-part story, we will focus on low-light and medium-light plants.

LOW-LIGHT PLANTS. These plants thrive on a light regime of 75 to 150 footcandles. In fact, a plant in this category can tolerate months at the lowest light intensity before deterioration is evident. The plant must then be cycled to a site where the light intensity is higher for recovery.

Aspidistra elator. The Cast Iron Plant is the champion of low-light green plants, ideal for massed understory foliage plantings where light tends to be scarce. Even in a sunless window, they will thrive and grow. They are temperature indifferent, doing equally well in hot or cold locations, but do not overwater. The top two-thirds to three-quarters of the potting mixture should be allowed to dry before watering again.

Chamaedora elegans. The Parlor Palm is a shrubby, clump-type plant that grows well in large containers or pots. It has a high moisture requirement, is slow growing and has the potential to reach 6 feet in height and 4 feet in spread. The Parlor Palm is ideal for office or room situations where essentially no outside light is available and the prime or only source of illumination is fluorescent lighting from the ceiling.

Dracaena deremensis ‘Janet Craig’ and Dracaena terminalis ‘Ti.’ These are erect, cane-forming plants, reaching more than 6 feet in warm, moist environments. The Dracaena terminalis ‘Ti’ is often sold under the scientific name Cordyline terminalis ‘Ti.’ Both are durable, but the Jane Craig is susceptible to fluoride tip burn – a browning of the foliage tips. ‘Baby Ti’ is a rare cultivar of this type with foliage edged in red, and it grows no larger than 3 feet.

Philodendron miduhoi and Philodendron cordatum. Both make good vines for massing in planters or as hanging basket specimens. They are majestic in motel solariums where they can hang from balconies and trail down to the lower levels. They will benefit from occasional – usually yearly, depending on the growing site – pruning back to thicken and control sometimes-rampant growth.

Spathiphyllum spp. Peace lilies are good massing, ground cover plants that do best when used as understory plantings in raised interior planters. They require plenty of moisture and tolerate low-light conditions the best of all low-light plants. To show their classic flowers, however, they need 100 to 150 footcandles of light.

MEDIUM-LIGHT PLANTS. These plants require 200 or more footcandles to thrive.

Anthurium scherzeranum. The Flamingo Flower is a showy plant, and two other species, A. andraeanum and A. crystallinum, are worthy of indoor consideration, as well. Known for their brightly colored flowers, these eye-catching plants require ample amounts of water, and they like temperatures of 65 to 70F. They are best used as massing plants or individual specimens. The flower stalks may need staking with slim bamboo to provide support, and be sure to mist the plant frequently and provide high humidity.

Aaucaria heterophylla. The Norfolk Island pine is among the most popular of indoor plants, with lush, supple, needle-evergreen foliage, beautiful symmetry of growth and relativity easy care. Start as a terrarium plant and in 12 to 15 years, it could reach an 8-foot ceiling. Uniform moisture and light intensity are important as well as cooler temperatures. Provide supplemental lighting during long, dark winter months to prevent needle drop.

Brassaia actinophylla. The Schefflera is another popular interior plant that starts small and grows big. Do not allow foliage to get wet during regular watering, as this may encourage fungal diseases. These plants like warm temperatures and moist soil, and they can be kept bushy with regular pruning.

Chamaedora spp. Reed and Bamboo Palms can be useful in low to medium light situations where fullness and height are required. Keep soil moist and air temperature warm.

Chrysalidocarpus lutescens. The Areca Palm is another good plant to use when massed effects are needed. However, it is sensitive to light and watering relationships and can be troubled with foliage yellowing. Avoid excessive water or fertilization and never allow the pot to stand in water.

Cycas revoluta and C. circinalis. One of the few cool-climate palms, the Japanese Sago has stiff, green foliage, while the Queen Sago has softer foliage and grows more upright. Both species have stout trunks.

Dieffenbachia amoena. The several species and cultivars of this plant, including Giant Dumb Cane and Mother-in-Law’s Tongue, are decorative foliage plants that can attain heights of 5 to 7 feet. They will benefit from bright, indirect light during the summer months and can take a direct window location during weaker light months. Dumb canes are susceptible to overwatering, so allow them to dry before watering. After handling these plants, be sure to wash hands thoroughly, as the sap contains large amounts of calcium oxalate that causes swelling, pain and temporary loss of speech, hence, the origin of one of the common names – dumb cane.

Dracaena marginata. These are used for accent in the interiorscape or for the unique shapes they take. While they may look delicate, they are durable and able to tolerate low light. Although susceptible to fluoride tip burn, this plant tolerates drying out, even preferring a dry soil.

Ficus benjamina. This durable plant can grow into a head-turning tree form. The lustrous, dark green, pointed leaves can densely cover branches. The plant can survive occasional drying out, and it can be kept inbounds and in a bushy form with regular pruning.

icus lyrata and F. decora. These are real broad-leaved beauties. Both tend to be sensitive to drafts, wide fluctuations in watering or water that is too cold. Attention to these details will produce attractive and otherwise durable plants.

Livistonia chinesis. The Chinese Fan Palm periodically needs higher than average light intensity – up to 500 footcandles – to look best. With gracefully arching fronds and fringed tips, the plant takes on a more graceful look with age and is perfect for office entrances where a good first impression is desired. A similar plant, the Kentia palm, has a deeper cut leaf frond, grows slower and will eventually require considerably more room, possibly growing 8 feet tall and 10 feet wide.

Radermachera sinca. The China Doll is lushly green and symmetrical, but it is fussy, and watering should be even. It does well in direct light and normal room temperature. If the soil dries, the leaves will drop. Keep fertilized during active periods of growth in spring and summer, and keep an eye out for aphids and mealybugs, which can become a problem.

The author is an extension horticulturist and turfgrass specialist with North Dakota State University, Fargo, N.D. Visit Lawn & Landscape Online next week for the conclusion of this two-part story. For more information on interiorscape issues, visit Interior Business magazine, Lawn & Landscape magazine's sister publication.