Watering

Equally important as light is the amount of water plants receive. Yet many gardeners are too conscientious in this respect: the tendency to overwater is so common that it is estimated that more plants die from this than anything else. A plant’s roots must have air as well as water. If the soil is constantly saturated, air is driven out, the roots rot and the rest of the plant dies.

Flush new plants with water after first bringing them home, but in subsequent waterings, be careful not to drown your plants. A sign of over-watering is that leaves yellow at the base. In severe cases, leaves drop off without changing color. Such an abrupt leaf loss generally signifies irreparable root damage caused by a disease called Pythium (or Root Rot). About all you can do is to discard the plant, learn from the error and start over again.

Of course, there’s such a thing as underwatering too. Its primary symptom is wilting leaves, starting with the youngest ones at the tips of the stems. The older leaves, having larger, tougher cells, may not show any effect for a few days or more, but soon their edges begin to turn brown. If you catch the plant at the browning stage, there may be time to save it with watering; though the edges will not turn green again, they can be cut off with scissors.

It is not always easy to gauge the right amount of water. The needs of different species vary, and the needs of a particular plant may also change with the temperature of the room, the cloudiness of the sky outdoors and the size and material of the plant’s container.

In general, plants fall into three broad categories of moisture requirements: water-loving plants, such as Dracaena and Creeping Ficus, demand a soil that is constantly moist, but not so wet that it feels soggy to the touch. Other plants such as Gold Pothos and Ivy should be allowed to become moderately dry between thorough waterings. Plants such as Peperomia and Hoya should be kept barely moist at all times.

To tell how moist or dry the soil is, you can poke your finger down into the soil about 1/2 inch and gauge by feel. Also, if the size allows, pull the plant out of its pot and see how dry the soil is underneath. Very often the top surface of the soil is dry and the rest is completely saturated.

Many problems connected with watering can be traced to improper drainage. Foliage plants can be grown in almost any container - from an old tomato can to a priceless Grecian urn—as long as excess water is not allowed to collect in it. Most plants are sold in simple flowerpots of clay or plastic with one or more drainage holes at the bottom. Bear in mind, however, that clay pots, because their walls are porous, lose moisture by evaporation about three times as fast as plastic ones and should be checked more often for dry soil. Plants in plastic pots should be watered less frequently.

In addition to standard clay and plastic pots, there are many kinds of decorative containers that do not have drainage holes. You can add holes by drilling carefully through the bottom with a special masonry bit. But the very lack of holes is appreciated by many people because it keeps water off the floor without need for a saucer. Never let plants sit in saucer of water for a long time unless trying to saturate extremely dry soil.

Tips on Watering Foliage House Plants

Regardless of how a plant is potted, there are a few basic tips on watering.

• Use tepid water. Simply, tap water that is pleasantly warm to the touch. Plants take up tepid water more readily than cold water, and cold water can shock many plants and cause them to wilt.
  
  
• Let chlorinated water age. If your water is heavily chlorinated, let it stand in a pan overnight before using it on your plants so the chlorine can evaporate. Do not use water from a water softener unless it is equipped with a deionizing unit to remove the sodium used in the softening process; neither chlorine nor sodium is beneficial to plants. Rain water is a good source.
  
  
• Go with the flow. When you water a plant in a standard pot with drainage holes, add water until some comes out of the holes.
  
  
• Oops, too much. Beware of water coming out too quickly. If the ball of soil around the roots has been allowed to become overly dry, the soil may have shrunk and pulled away from the pot’s walls, and the water you have applied has just run down the gap on the inside of the pot, completely bypassing the roots. In such a case take the plant, pot and all, and immerse it in the sink or in a pail of water one inch deep and let absorb. Thirty minutes later set the plant aside so the excess water can drain.