Imagine walking into a home full of green plants. When you open the door, the area greets you with an unmistakable feeling. The air is alive and clean, full of positive energy. The plants seem to be giving off not only oxygen, but good vibrations.

A home with indoor plants not only feels different, but also, science is now proving, it really is different in a very healthy way.

Most people would agree that the extra oxygen provided by indoor plants is a healthy benefit. But evidence gained during 25 years of research shows that the benefits of indoor plants might not be from what they give off, but from what they take in.

Most houseplants literally eat chemical pollutants, the same pollutants that pervade our homes and offices and are responsible for health issues ranging from sore throats to asthma, and even cancer. For less than the price of one visit to the doctor, houseplants can clean the air in your home or office.

If you think the idea of plants as health agents is just another traveling medicine show, it's not. This week, the Wall Street Journal again touted the benefits of houseplants as air purifiers and NASA has been doing research for decades on their potential as air scrubbers.

In fact, NASA's groundbreaking research on indoor plants found that they were so efficient at absorbing contaminants in the air that houseplants will be launched into space as part of the biological life support system aboard future orbiting space stations.

While research is continuing, several studies show that many common houseplants can remove various pollutants from indoor environments. Many experts feel that indoor plants will soon be seen as standard components of pollution-free homes and workplaces.

Indoor air pollutants can be broken into two groups: gases and tiny airborne particles. Remarkably, laboratory research has determined that indoor plants can effectively reduce health threats from both. Plant leaves are effective at reducing harmful gasses, while the soils, roots and accompanying microorganisms of potted plants are important in removing various particulate pollutants.

Modern homes can be a minefield of chemical hazards. Carpets, furniture, insulation, paint, paper and even fireplaces can emit pollutants.

Formaldehyde is released from a host of household furnishings. Xylene, benzene, trichloroethylene (TCE), toluene and carbon monoxide are just a few of many invisible pollutants that can cause an array of health issues. Benzene is a commonly used solvent in such items as gasoline, inks, oils, paints, plastics, rubber, detergents, dyes and many pharmaceuticals. TCE is common in dry cleaning, printing inks, paints, lacquers, varnishes, adhesives and many other items.

Common house plants are inexpensive, ecologically sound, aesthetically pleasing and, best of all, are silent warriors against these pollutants. A single Boston fern can remove an astounding 1,800 micrograms of formaldehyde from the air in about an hour; that's as good as many expensive air filtering systems.

Some plants are better than others at filtering certain pollutants. Areca palms, for example, are an effective filter of xylene, while Boston ferns, chrysanthemums and dwarf date palms are better at removing formaldehyde. Old fashioned spider plants were found to be very effective at dealing with carbon monoxide and in tests removed more than 96% of this potentially deadly gas.

The Foliage for Clean Air Council recommends one to two 6- or 8-inch plants per 100 square feet of floor space in a home with normal height ceilings. If you're not ready to fill your house with plants, start on a smaller scale by selecting plants that are especially effective at removing the most worrisome pollutants.

In tests, the top four species were Boston fern, English ivy, areca palm and spider plant. If you've recently installed new furniture or carpeting, place one or two Boston ferns in each of the rooms.

English ivy is especially effective in a room that has been recently painted or carpeted as well as those that contain plastic equipment or ink, like computers, printers or fax machines. Areca palms can be used in almost any room, but are especially useful in those that are carpeted or contain freshly varnished furniture. Because spider plants are so good at removing carbon monoxide they are useful in kitchens with gas stoves or in rooms with fireplaces.

It's now certain, a home with indoor plants not only feels different, it is different. It's healthy.

RON VANDERHOFF is the nursery manager at Roger's Gardens, Corona del Mar.

Ask Ron

Question:

Is it finally time to plant my tomato? I can hardly wait any longer.

Barbara, Laguna Beach

Answer:

Go for it, Barbara! Plant to your heart's content. As you may have read here, I'm not a big fan of planting tomatoes too early. Fortunately, we have definitely entered into the perfect tomato planting time. If you have room, be sure to plant some variety. Start with a standard red slicer, then a big beefsteak type, at least one cherry and perhaps a plum tomato if you make your own sauces. Now, you'll also want various colors, like purples, blacks, pinks, whites, yellows and even stripes. Surely, you can't just grow one tomato!

ASK RON your toughest gardening questions, and the expert nursery staff at Roger's Gardens will come up with an answer. Please include your name, phone number and city, and limit queries to 30 words or fewer. E-mail stumpthegardener@rogersgardens.com, or write to Plant Talk at Roger's Gardens, 2301 San Joaquin Hills Road, Corona del Mar, CA 92625.