Watering plants may be a rather mundane part of your weekly routine. However, the amount of water, frequency and quality of the water are critical to the health and beauty of your plants. On a weight basis, most plants are 85 to 95 percent water.
Water pressure prevents the leaves and flowers from drooping. The constant flow of water through a plant maintains the nutritional and hormonal balance in the various parts of the plant. Water is also necessary for many of the biochemical reactions within plants.
Over-watering or under-watering are common problems for indoor gardeners. Roots do not function properly in an over-watered soil due to the lack of oxygen. When plants are underwater, the roots are damaged from the lack of moisture and excessive salts that occur in a dry planting medium. Both conditions cause the plants to wilt, turn yellow, drop leaves, and eventually, the plants may die.
The frequency that houseplants need to be watered depends on these factors: the plant’s individual water needs, the location of the plant in the home, and the size of the container and the type of potting medium.
Some plants prefer soil that is somewhat dry, such as many of the succulents. Others, such as African violets, baby tears and ferns, require a soil that is moist most of the time. If the plant is in a bright window or under supplemental lighting or in a warm draft, it may require water more frequently. If a small plant is growing in a large container, you may not need to water the plant as often as the same sized plant growing in a smaller container. A well-drained soil will hold less moisture than a “heavy” organic soil and will require watering more often.
When watering your plants it is important to water them thoroughly each time so that the excess water drains through the soil mix and out through the drainage hole in the bottom of the container.
Empty the excess water from the saucer so that it does not seep back into the root environment. This is important to prevent the accumulation of excess salts in the soil.
Although it sounds silly, the water used on houseplants should be room temperature. If the top of the plant is warm and the water applied to the root zone is cold, the roots will not function actively enough to provide the needed water. Either let the water sit for an hour or so before watering or apply tepid water.
If you want to water plants properly, you need to pay attention to the quality of the water. Tap water can be used but with some precautions. Many gardeners are concerned about the chlorine in the water systems and its effect on the plants. Research has shown that chlorine is relatively harmless to foliage plants. However, the fluoride in water systems can cause problems for some plants. Many cities use fluoride in their water treatment programs to help slow down the process of tooth decay. This amount of fluoride is not harmful to plants; however, fertilizers and perlite in the soil media can add to this amount. Fluoride toxicity may appear as browned margins and tips with a yellow halo on sensitive plants such as Dracaena, spider plant and baby doll ti.
If your tap water has gone through a water softening system, do not water your plants with it. Softened water replaces the calcium and magnesium ions with sodium ions. This concentration of sodium and other salts is much too high and can cause tip and margin burning on the leaves and result in overall poor plant growth. Use water from the hard water tap. Rain water, melted snow and water collected from dehumidifiers are good sources of water for your houseplants. You may want to purchase distilled water if you have a special or rare plant in your collection.