Plants at Work, Indoors

Plants at Work is a national information program of the green industry to inform businesses and the public of the benefits of using plants indoors. Studies have shown that plants in homes and workplaces help reduce stress, increase productivity, enhance employee attitudes, lower operating costs, help in “green building” design, and improve air quality.

Studies in Texas, Washington State, and England showed that employees in environments with plants were 12 percent more productive than those not exposed to interior plants. Visual exposure to plants helped to reduce blood pressure, and to lessen stress within five minutes. Perhaps some of this arises from the reduction in office noise with the use of plants, another factor well-documented in studies. For instance, a small indoor plant hedge around a workspace can reduce noise by five decibels.

Surveys and studies have verified the positive effect of plants on employee perception and disposition. A key incentive for firms to have interior plant design and maintenance contracts is this, as well as employee retention. Plants have been shown to reduce employee absenteeism by 14 percent. It is cost effective to keep the employees happy, this asset valued at 10 times the building operating cost and 100 times the energy cost.

Plants cool by the process of “transpiration”, releasing moisture into the air. A USDA estimate is that proper use of plants could decrease air temperature in an office by as much as ten degrees. Plus, the moisture released by these plants helps maintain indoor humidity in the human comfort zone of 30 to 60 percent, and helps prevent materials such as wood from cracking when dried out.

The main effect of plants on buildings environments, however, may be on the outside. One young healthy tree, according to the International Society of Arboriculture, has a net cooling effect equivalent to ten room-size air conditioners operating 20 hours a day. Other industry statistics indicate the proper use and placement of trees can lower heating and cooling costs by up to 20 percent.

Similar to outdoor plants, indoor plants improve the perceived value of spaces in addition to the aesthetics. A study in England reinforces that indoor plants have a positive effect on perception, while costing less than most other choices for corporate décor. Clients and employees perceive interior spaces with plants as more welcoming, relaxed, and upscale.

An often cited example of the positive effect of plants on perception and value is the study of the Opryland hotel in Nashville. Its 85 percent occupancy is considerably higher than the 68 percent national average. A scientific case study found the main factor accounting for this high occupancy is the significant investment (over $1 million) in interior plants, in fact one of the largest investments in indoor plants in the country. This hotel has 12 acres of indoor space, containing about 18,000 indoor plants representing over 600 species.

A study over 20 years showed that interior plants can have a positive impact on “sick building syndrome.” This is the condition found in many tight, energy efficient buildings from indoor pollutants. These are the toxic chemicals from building components such as carpets, paints, and synthetic construction materials. Toxins include such compounds as xylene and benzene, with the most commonly found in EPA tests being formaldehyde at 0.173 micrograms per liter of air. Such tight buildings can be ten times more polluted than air outside or in “leaky” environments. An adequate installation of plants in sealed U.S. offices could save, by one estimate, $258 billion.

Rooms filled with plants were shown to have 50 to 60 percent fewer molds and bacteria in the air than in rooms where no plants were present. These, and toxins, both are absorbed in the soil, and into plant leaves. Toxins may be translocated down into the root and used there as plant food, or destroyed through a process called “metabolic breakdown” as shown in a study by German scientists.

Plants grown in potting soil have been rated for their relative removal rate of toxins, such as formaldehyde. For this compound, Boston fern can remove 1863 micrograms per hour, bamboo palm 1350, Janet Craig dracaena 1328, English ivy 1120, peace lily 939, areca palm and corn plant 938 for examples. All the details of how plants clean such air, and how to use them for this, are in the paperback book by the researcher B.C. Wolverton.

In another fascinating study by a university professor Tove Fjeld in Oslo, Norway, plants were shown to improve employee health in offices, schools and hospitals. Plants were included ornot in offices during various periods for employees. When plants were present, ailments such as fatigue, headache, sore throat, coughs, and dry skin were all reduced. The mean reduction of 12 ailments with plants present, compared to without, was 23 percent.

U.S. researchers Fisk and Rosenfeld of the Berkeley National Laboratory have quantified this into a $58 billion annual savings from sick-building illness with the use of plants, 40 percent of all sick days related to poor indoor air quality in their study. In addition, they estimate an additional $200 billion could be saved using plants indoors from improvements in worker performance.

You don’t have to think big to benefit from the use of plants indoors. A Scottish brewer is an example of a firm that uses plants indoors extensively, including planters on top of filing cabinets to divide space, reduce noise, and to improve employee health and satisfaction. For office workers, just having a plant on the desk can improve the six to eight cubic feet of “personal breathing zone” where most the day is spent. Author Jay Naar suggests 15 to 20 plants can clean the air in a 1,500 square foot area.

You can learn more about the Plants At Work program, and the “green” qualities of using plants indoors, at their website (www.plantsatwork.org)

Article Source: http://www.article-exposure.com

Leonard P. Perry, Extension Professor, Univ. of Vermont Checked out Perry's Perennial Pages lately? www.uvm.edu/~pass/perry/

All-American Selections - 2007 Winners

Each year the best new flower and vegetable selections that bloom or fruit the first year from seeds are judged in the All-America Selections program. Those that are proven best across the country in trials as new, or an improvement over existing varieties, are given the coveted All-America Selections award. This year the winners include three flowers and one vegetable.

Fresh Look Gold Celosia, or plumed cockscomb, joins its fellow and previous winners Fresh Look Red and Yellow. Reaching about a foot high, and almost that across, its dense golden plumes last well through the season with no browning. These plumed celosia, and this series in particular, are some of my favorite annual flowers as they are carefree with virtually no pests or problems. Just give them some fertility (they are not as demanding as many new annual flowers), full sun, and a well-drained soil. If starting them from seed, figure about 110 days from sowing to first flowers.

Opera Supreme Pink Morn Petunia is one of the newer trailing types, with many smaller flowers (two inches or more wide). Flowers are bright pink with white centers, and a yellow deep center or “throat”. These three colors make it a “morn” type. These colors, with a silvery cast, are eye catching from a distance.

Plants of this petunia flower continuously, with no need to “deadhead” or remove spent flowers, or cut back as was needed with older selections. In good locations, a plant can cover three feet, at about six inches high, keeping down weeds and covered with flowers. They grow best in full sun and a well-drained soil. Figure on spacing plants about 18 inches to two feet apart, and sowing seeds about three months or more before flowering.

Pacifica Burgundy Halo is another vinca, or annual periwinkle, to win this award in recent years. Flowers are a gorgeous burgundy with contrasting white center, the first such color combination in this genus of flowers. This vinca also has early flowers, good branching, and in my north country trials flowered through the season. Many older vinca need lots of heat in order to flower well.

As with the other annual flowers, vinca needs full sun and a well-drained soil. This annual, however, is quite drought tolerant when established and needs less water. Keeping under a foot high, plants should be spaced about eight to ten inches apart. Figure about two months from sowing to first flowers.

Holy Molé pepper is the only vegetable award winner this year. It is a pasilla-type pepper, the type used to make molé sauce. It won over other selections being earlier to fruit, vigorous, and with a high yield of fruits. One reason for the high yields is the resistance bred into this selection to two common viruses that cause peppers to be shorter and with less fruit.

Immature green peppers can be harvested about three months from transplanting, and are seven to nine inches long. Left on the plant, the peppers turn a dark chocolate color. Their taste is nutty and tangy. With plants staying between one and two feet high, space them about two feet apart. Full sun and a well-drained soil are needed, and the hotter the site the better. Sow seeds indoors early in order to transplant larger plants outdoors, as they need about four months from sowing to flowering.

Article Source: http://www.article-exposure.com

Leonard P. Perry, Extension Professor, Univ. of Vermont Checked out Perry's Perennial Pages lately? www.uvm.edu/~pass/perry/