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Houseplants add another dimension to our life by bringing some of nature indoors to our home or offices. It not only adds to the décor, but contributes to our over-all sense of wellbeing and makes the air healthier. Plants release oxygen and moisture to the inside air, in addition to removing toxins, called volatile organic compounds.


To get started with houseplants, obtain the OSU fact sheet HLA-6411, “Houseplant Care”. This has complete information about houseplants, as well as a suggested list of plants.


Which plants you choose depends on your personal preferences as well as the temperature, humidity and amount of light available in your indoor area. Many plants such as philodendron, dracaena, ferns and ivies are selected for the green foliage. Some of the plants grown for blossoms include African violets, peace lilies, orchids and poinsettias.


Growing Basics:


          Light: Some plants need more light that others. Inadequate light will lead to plants becoming tall, spindly and unhealthy. If lighting from outdoors is not sufficient for your plant, various types of growing lights are available.


          Temperature and Humidity: Most houseplants prefer a temperature of 65-75° and a humidity of 50-60%. Humidity may be increased around the plant somewhat by placing the pot on a tray of moist pebbles. Avoid locating the plant in the path of air vents with either hot or cold dry air, this will kill most plants.


          Watering: Plants will need irrigation in varying amounts and it is essential to know the water requirements of your particular plant for success. Houseplants that die usually have had either too much or too little water. Most potting soils drain rapidly and more frequent watering will be needed than those out in the garden.


The best approach to watering is to let the pot almost dry out between irrigations, then water to the point of runoff from the bottom of the pot. Discard this water; it has undesirable salts left over from fertilizers. Because accumulation of salts is such a problem in houseplants many people suggest flushing your pots with 2-3 pot volumes of water twice yearly. You can also put your plant in the shower to both irrigate the soil and wash the off dust and pests from leaves.


          Fertilizing: Fertilizers may be liquid or slow release pellets; both are useful if directions are followed. Don’t over-do it, plants are easily “burned” if too much fertilizer is used.  Most houseplants essentially stop growing during the shorter days of winter and will need much less or no fertilizer depending on the plant and light.


Troubleshooting Houseplant Problems:  


          Non-insect or Disease Problems: Yellow leaves which drop from the plant is a common occurance and is often due to too much water. Leaves also yellow when the humidity is low, or after the plant is brought in from the outside to a lower light environment.


Wilting of plants may be related to inadequate water or, surprisingly to some, too much water. Excessive water smothers the plants roots making them unable to absorb water, causing wilt.


Brown leaf edges may occur due to dehydration, but a very common cause is excessive residual fertilizer salts in the potting soil. Proper watering will prevent this.


All plants may outgrow their pots and become “pot bound”. When they do, they will grow poorly and appear stunted. Inspect the roots; pot bound plants will have many close-knit roots which are brownish, rather than a healthy white appearance. The solution is to repot in a larger container 1-2 inches larger than the current one.


          Diseases: The chief disease problem of houseplants is root rot associated with excessive watering. When this occurs, you may need to start over.


          Insects and pests: The chief insect problems are related to aphids and mealybugs (a type of soft scale). Less commonly spider mites and white flies may be problematic.


Isolating the plants and hosing them down will remove many of the pests. You can also submerge the plant in water for about 30 minutes to rid the plant of some of its insect infestation. Small infestations, especially with mealybugs can be controlled with a cotton swab and alcohol.


If an insecticide is needed, its best to use a safe organic insecticide. This includes horticultural soaps, horticultural oil (such as Neem Oil) and pyrethrin. Always follow the labeled directions when using any insecticide.


Another common insect problem is fungus gnats. These are tiny gnats that reproduce in the top layer of the soil. Eggs are deposited and larvae feed and thrive in the top ½ inch of the soil. This is due to soil being kept too wet. The adults are tiny flies which are a nuisance but do no harm. Control involves letting the top of the soil dry completely between watering. If an insecticide is needed, Gnatrol is a special Bt type organic insecticide which is safe to use in the home.