Home Garden Aug. 2002 HG- 43
Enhancing Your Länai, Balcony, or Patio with Container Plants
Richard Criley Department of Tropical Plant and Soil Sciences
he environment of a länai or an apartment balcony is generally not hospitable for plants. Winds dry the soil and dehydrate the foliage. The sun heats the pot, medium, and plant, causing poor root development, wa- ter loss, and stress on the photosynthetic factory. Soil microorganisms are also affected and exist at low popu- lations. T
While the environment may be inhospitable for plants, insects still seem to thrive. A lack of familiarity with plant needs (water, fertilizer, drainage, light) may lead the apartment dweller to ignore regular watering and fertilizing, cleaning, pruning, and examination for pests.
However, if plant selection and maintenance are done with proper forethought and care, länai plants can enhance the outdoor environment.
Länai plants may be grown in small or large pots made of plastic, ceramic, clay, or cement. Some may be as small as 2 inches across and others may be classified as tubs or even built-in planter boxes. The small amount of space on most lanai leads to crowding, double-deck- ing, use of hanging baskets, and even over-the-rail win- dow boxes (often frowned upon by condominium man- agers and owners’ associations).
Plants in such containers must be carefully selected for color, form, vigor, tidiness, and adaptability to the conditions of the länai. That said, there are many plants that will survive and even thrive if small modifications are made to this stressful environment.
Aspect South-facing and west-facing länai may almost be con- sidered to have a different growing environment from north-facing and east-facing länai. The sun’s heat and
drying influence are great on the former, while Hawaii’s trade winds exert their drying influence on the latter. Light intensity changes with the angle of the sun through the year, and a north-facing länai may still have high morning light while providing shade in the afternoon.
Choice of container The container must be heavy enough not to tip over with the plant in it, and large enough to support the plant’s root system and be in proportion to the top growth of the plant. The pot must have drainage so water does not accumulate around the root system. Containers may be ornamental or merely functional.
Light-colored pots tend to reflect some of the inci- dent light and heat that stress plant roots; dark-colored pots absorb heat and contribute to faster evaporation.
Choice of medium There is no such thing as a perfect medium. It is com- mon to buy plants at a garden center that have been grown in a porous, lightweight medium such as peatmoss and perlite. This medium dries readily, is difficult to re- wet, and is marginal in being heavy enough to keep a large-crowned plant from blowing over.
The bags of medium sold at garden centers may be satisfactory from the standpoint of holding moisture and providing drainage, but many fail the “weight” test.
The common practice of putting large rocks, bro- ken clay pots, or coarse gravel in the bottom of the pot for drainage is probably better for weighing the pot down than providing drainage. This is because water tends to stay in the small pores of medium above the coarse drain- age material rather than move into the large pores.
Published by the College of Tropical Agriculture and Human Resources (CTAHR) and issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Andrew G. Hashimoto, Director/Dean, Cooperative Extension Service/CTAHR, University of Hawaii at Manoa, Honolulu, Hawaii 96822. An Equal Opportunity / Affirmative Action Institution providing programs and services to the people of Hawaii without regard to race, sex, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or veteran status. CTAHR publications can be found on the Web site <http://www.ctahr.hawaii.edu> or ordered by calling 808-956-7046 or sending e-mail to firstname.lastname@example.org.