Fact Sheet Maintenance of Interior Foliage Plants

There is no such thing as a "house plant." Plants grown in interior spaces actually come from tropical or arid regions and must adapt to less than ideal conditions in the home or office. The gardener's challenge is to know the plant's environmental needs and meet them. The interaction of environmental factors and maintenance practices contribute to the health or decline of the plant. Light Characteristics of light to consider include intensity, quality and duration. Intensity refers to the amount of light present and will vary by season, shade cast by objects outdoors, cloudiness, or by window treatments used. Intensity decreases greatly from outdoor to indoor spaces and can vary greatly within a single room. A southern exposure indoors typically provides the greatest light intensity, then western, eastern, and northern. Plants with variegated foliage have less chlorophyll and therefore require more light to achieve the same photosyn-thesis as a plant with green foliage. If light is insufficient, variegation may be lost. Flowering plants also require higher light intensity. As winter approaches, light intensity and duration will diminish. A plant that grew well in an eastern exposure in the summer may require a southern exposure in the winter. Move plants to other locations seasonally if needed. Symptoms of insufficient light intensity include: weak growth; long, spindly stems; poor color in older leaves; and leaf loss or failure to flower. Quality of light refers to the spectrum or colors available; sunlight contains all colors. Plants utilize all colors in photosynthesis. An incandescent light bulb emits limited colors and is not acceptable as an indoor lighting source for plants. To grow plants under artificial fluorescent light, most indoor gardeners combine a cool and warm tube in a fixture to provide light of good quality for many interior plants. "Grow lights" emit the required light; these fluorescent tubes are more costly than others but last longer. Duration refers to the length of light exposure. A daily exposure to light, preferably 8 to 16 hours, is needed for plant processes. Symptoms of insufficient duration are similar to those of low light intensity; small leaves, spindly stems and older leaf drop. Temperature The ideal temperature range for most interior foliage plants is between 60F and 80F, similar to that found in the understory of a tropical forest. Chilling injury occurs below 50F for some tropicals. Air temperature is quite variable within a home or office and can change daily or seasonally. Exposure may affect temperature; typically, southern and western exposures are warm because of sunlight, while eastern and northern are moderate or cool. Avoid locating plants on cold window sills, or where there are cold or hot drafts from opening doors and heating or air conditioning vents. Symptoms of cold damage to plants include: leaf spots or blotches; downward curled foliage; slowed growth; and root rots. Excessively high temperatures cause yellowish green foliage which may have brown, dry edges or tips and spindly growth. Insect, mite and disease problems may develop quickly under warm conditions as well. Maintenance Overwatering a potted plant is perhaps the leading cause of death. Roots that are surrounded by water and have little oxygen available soon rot, eventually killing the plant. Unfortunately, the symptoms of overwatering and under watering are similar. Both lead to chronically poor root health, decline and eventually death. It is impossible to impose a strict watering schedule because a plant's needs change. Need can change depending on a number of factors: the plant species; the type and size of pot; soil mix characteristics; variable weather conditions; and how fast the plant is growing. For example, the same plant that uses abundant water when the weather is hot, dry and sunny, will use less water when conditions are cloudy and damp. Plants may slow in growth after a period of heavy bloom, after a flush of new growth, or during a prolonged period of dark or cloudy weather. Be especially careful not to overwater such plants. The best way to determine when a plant needs water is to feel the soil mix with your finger tip. If cool and barely moist to the touch, the plant is considered moderately moist. If the soil mix is slightly moist, or questionable, it is best to wait another day or two and retest before watering. Cacti and succulents can tolerate greater dryness; let the soil become crumbly dry for several days before watering. Another method to determine when to water is to use the weight of the container. A dry container and soil mix will be lightweight compared to one that has just been watered. Most plants do well when the soil mix is "moderately moist." After watering thoroughly, allow the soil mix to dry to a slightly moist condition before watering again. Completely saturate the soil mix with water to fill all the pore spaces. Pour enough water into the pot that it drains out through the drainage hole. This method is also beneficial in leaching out excess fertilizer salts in the soil, which build up over time. It also exchanges the air in the soil mix. Do not allow drainage water to seep back into the soil mix; empty the saucer of excess water as soon as the container drains completely. Do not allow the soil mix to dry excessively. If the salt level is high in the container, root damage can occur. If a plant's soil mix is excessively dry and hard to rewet, try double watering. Water once and then again half an hour later; or place the pot in a sink or bucket filled with water. Remove it from the sink or bucket when the soil surface is moist. Allow the pot to drain after using one of these methods. Plants should not be watered with hot or cold water. A water temperature between 62F and 72F is good. Do not water plants with softened water which adds sodium and chloride to the soil mix and could cause plant damage. Call For Price 440-320-7854