Green thumbs thrive on high humidity

Did you ever wonder why plants growing in terrariums or greenhouses are so lush, green, and vigorous? The answer is simple: high humidity. A well-maintained greenhouse, for example, has a humidity of 75 to 85 percent. In the average home, it is 20 to 30 percent.

Plants with brown tips on their leaves are displaying a typical stress signal that means more humidity is required. A hot, dry atmosphere will cause the leaves to drop and often kills the plant.

Humidity indoors or outside is dependent on many factors, such as temperature , pressure, and the like. The warmer the air, the more water it can hold without becoming saturated.

The amount of water vapor in the air compared to the amount required for saturation at that temperature is called the relative humidity. If the air contains only half the amount of moisture it would need to become saturated, the relative humidity is 50 percent.

It is easier to maintain an excellent humidity rate in a home if the temperature is never above 70 degrees. The ideal temperature for many plants is 65 degrees during the day, 50 to 60 degrees at night. Warmer air will absorb more moisture from houseplants.

Additional humidity may be achieved by misting with a spray device at least once a day. Spray or mist bottles may be bought at variety stores for a nominal price; garden stores and mail order houses sell adjustable misters in a wide price range. The latter will emit a fog-type spray that is ideal.

Cactuses and succulents have a different evaporation-breathing system than plants with leaves. As the cactuses and succulents thrive on warm, dry air, misting is not recommended.

A frequent sponging with a soft cloth will remove dust and eliminate clogging of the pores. Many varieties can be placed in a sink or shower and gently washed with a solution of one-eighth teaspoon of liquid soap (not detergent) to a quart of water. Plants with hairy foliage should not be placed in sunlight while the leaves are wet.

The water used for this cleansing and for soil moisture should never be taken from a water-softening system or from a source where chlorine has been added. Rain water or well water (or distilled water) is advised.

Also, containers of stones and water may be placed beneath or near the potted plants. The pot rests on the stones above water level. This water will rapidly evaporate, showing its need for being there.

Regardless of the methods used, clean leaves in a moist atmosphere reward indoor gardeners with thriving houseplants they are proud to display.