Thursday, November 8, 2007

Watering your plants

In the wild, water appears as rain, mist or fog and is taken up mainly by the root system. Plants in the home are reliant on us to meet all their watering needs. Water is essential to all plants; without it they will die. The length of time this takes may vary from one day for young seedlings to several months in the case of a succulent plant, but death will always occur eventually. Water acts as a transport medium, in the way blood does for animals, and it is also essential for the process of photosynthesis, which supplies the plant's food. Water from the potting mixture is passed by the roots to all parts of the plant, carrying with it the nutrients vital for the food-manufacturing process. It charges stems and leaves and makes them sturdy and plump (turgid); without it they cannot stay erect. Any shortage of water results in stems and leaves becoming limp and drooping, flowers fading quickly, and buds falling before they can open. A temporary drought often means that leaves shrivel and turn brown at the edges and the tips, making the plants look unattractive.

When to water

Knowing when to water can be difficult but, as a general rule, you should water potted plants when they need it. This may seem to be an over-simplification, but it is accurate. The real problem is to judge when that is. Drooping leaves and limp stems are obvious signs that more water is needed, but you should not wait for such an advanced stage to be reached. There are more subtle signs: some plants' leaves take on a paler, translucent look when water is needed; on others, the flower buds dry and shrivel. Each plant has its own watering needs, dependent on its size, its natural environment and, most importantly, the time of year; actively growing plants need a lot of water, the same plants can manage with much less during the winter rest period. Never water routinely just because someone tells you to water every so many days. It is far better to test the potting mixture first, as this will indicate whether or not the plant needs watering. "Weighing" the pot in your hand regularly can also give an indication of the amount of water in the potting mixture; a mixture that is saturated with water weighs more than one that is dry. This method is reliable, but it takes a little practice to gauge whether or not the plant needs water, and is not always practical with larger plants in bigger pots. Moisture gauges are available which record on a dial the exact moisture content of the potting mixture. Readings such as "wet", "moist" or "dry" can be seen at a glance and allow you to act accordingly. Quite simple small indicator "sticks" or probes can be bought which are pushed into the mixture and change color according to the moisture content. Generally, play safe and, if in doubt whether to water, wait a day or two before making the decision. This is because, though both under-and overwatering can cause damage to plants, overwatering is probably more usually fatal.

No comments: