They create oxygen and liven up a room, but administrators at Jefferson College of Health Sciences have decided plants are a mold problem waiting to happen.

Despite the trend over recent years to bring nature indoors, the college found that the potential for mold and mildew issues outweighed the benefits.

"It's kind of a cautionary thing," said Mark Lambert, spokesman for the college.

In a recent newsletter, the college reminded students and staff to keep their windows closed when the air conditioning is running and that all houseplants have been banned from the Reid Center.

The majority of the building houses classrooms, laboratories and offices, but the top three floors are dorms for students. The houseplant ban applies to the entire building.

An air-quality inspector made the recommendation during what was a routine look at the 10-story building, located at 920 S. Jefferson St., Lambert said.

Lambert said he didn't know who did the inspection and that the person with that knowledge is on vacation for the week.

The building is owned by Carilion Clinic. Typically, Carilion's in-house engineering staff do the air-quality testing for all Carilion buildings, said Eric Earnhart, a spokesman for Carilion. But in this case, Earnhart said he didn't know if the testing and recommendation for the Reid Center was done by Carilion staff.

Carilion does not have a ban on houseplants at any of its facilities, Earnhart said.

"Our lobby plants are professionally maintained, and it is our expectation that all employees have clean and professional work areas -- that would include appropriate use and proper maintenance of live plants they choose to bring in," Earnhart said in an e-mail.

Research has shown that indoor plants improve air quality in offices and also increase productivity and lower stress levels, said Stephanie Huckestein of Virginia Tech's Department of Horticulture.

"It is unusual to hear the claim that indoor plants are harmful," she said adding that an entire business called "interiorscape" has been built on bringing plants indoors.

Companies offering interiorscaping typically maintain plants for businesses on a contract basis. Jefferson College had used a professional service, but decided to discontinue the contract in making the decision to eliminate plants from the building, Lambert said.

Huckestein said plants that are not properly taken care of and are overwatered could produce mold, but that is rare.

The Reid Center has had mold and mildew problems in the past related to the age of the building, Lambert said.

The building, which was built in 1950, according to city records, does not have any mold or health problems, Lambert emphasized. The Roanoke City Health Department has had not reports of mold problems at that building, said health department spokesman Robert Parker.

The college's decision was not intended to discount the benefits of plants.

"I think it is more the moisture that we are worried about," Lambert said. "We don't have anything against plants. Plants are great. It's just a preventative thing."