Watering

Watering needs differ from plant-to-plant, and stage-to-stage of plant growth. Cacti and succulents have sufficient water reserves in their stems and leaves, and do not lose much moisture as compared to other plants, making them easier to maintain. In fact, excess watering is the chief enemy. Many such plants die from enthusiastic over,watering. This is because the air spaces between the soil particles are displaced by water, and if this persists over a period of time, the roots are deprived of oxygen and are liable to rot from fungal attack.

Plants need much more water when new leaves are being formed during the active growth period. In general, the more leaves a plant has, the greater is its need for water because water is transpired through the leaves.

It is useful to know two other factors that increase water loss through leaf transpiration. One is light-the more the exposure of the leaves to light, the more rapid is the transpiration. So, plants in small pots, with less water reserve, abundant foliage and kept in the sun may be drooping for lack of water before the day is over.

Most household plants do better in open-air shade than in the sun, so unnecessary sun should be avoided (see Light Requirements).

Temperature is the other factor governing water loss. Summer calls for bigger and frequent doses of water, sometimes twice a day. On hotter days, late afternoon watering is better, as by that time the soil becomes quite dry due to rapid transpiration around noon and so must be re-moistened. Noon-time watering must be avoided, as droplets of water on leaves become tiny magnifying lenses, and may cause scorching of leaves by concentrating the sunlight. However, the soil can be wetted without any harm if the plant is in need of water. In cold weather, when the foliage is scanty and the plant is dormant, the soil remains moist most of the time. The daily ritual of watering can then be avoided. And to keep the soil slightly moist, the plant should be watered, every alternate day to once a week. Clay pots lose more water due to porous walls, and so are safer when over-watering is done. Cement and plastic pots, being non-porous, hold water for a longer time, so their soil remains wet longer. Before watering wait till the soil is partially dry. However, soil should never be allowed to become parch dry as this will cause some of the roots to die and if this happens often the plant is likely to perish.

How Much Water: It is a wrong notion that pouring a little water to keep the soil always moist is good. The soil must be allowed to become somewhat dry between watering so that air can interact with it. Partial dry spells stimulate the roots to dig deeper for water. This ensures a healthy root system; well spread through the soil and not just clustered on the surface. When you water the plant, soak it well. Provide an Inch or more of empty space above the soil in pots, which can be filled up and left to drain through. Treat the beds in the same manner. If the water does not drain through in less than five minutes in pots, and up to 15 minutes in a bed, then there could be a soil drainage problem. (See Soil).

The first advantage of such a watering technique is that the total root zone is wetted. As the water drains, it also takes away the excess salts present in the soil, which would otherwise accumulate, making it less fertile. The draining away of water from below creates a suction, which pulls in fresh air from the top. In winter, when the plants may be dormant, do not flood them with water because the plants will riot absorb it. Pour just enough water to make the root zone lightly moist. To facilitate the wetting of the root zone using less water, pierce a few holes (6-12 inches deep) into the soil near about the stem of the plant. Use a pencil for pots and a rod for ground plants. Ground planted trees, shrubs and climbers, once established will anyway not need watering during the dormant season.

While the soil is getting watered, the leaves should also be sprayed to clean the dust from their surface. The plant should never be watered if the soil is already wet from previous watering.