Photo: Marcelo Cesar Augusta Romeo
Each and every landscaper worth his salt should incorporate a water feature – if only a modest fish pond – in his garden designs. And even apartment dwellers, with only a concrete balcony to link them to the open air, can think of focal points such as waterproof ceramic pots on plinths, decorated with water lilies or lotuses.. Low maintenance too. Apart from the occasional top-up, nymphaeaceae will happily survive the kind of extended dry spell we are currently experiencing. And if you introduce small fish such as guppies and swordtails, you will not only add interest , but ensure that your watery havens do not become breeding grounds for mosquitoes.
If lotuses and lilies are the aristocrats of aquatic plants, then duck weed (lemna) is the poorest of poor relations. Like all plants which float independently on a watery surface, it is simplicity itself to grow. Composed of tiny “leaves” no more than 2-3 millimeters across from which dangles a single submerged root, it usually arrives unannounced and within six to eight weeks, if unchecked, will form a dense brilliant green mat. Most people dislike it, but unsurprisingly ducks, and some fish, especially carp, and frog tadpoles, find it succulent. Personally I allow it a small corner in my fish pond where fry can shelter from their bigger brethren. Easy to control, it is difficult to eradicate entirely.
Another floating plant which is also classed as an invasive weed in some parts of the globe is the water lettuce or pistia stratiotes. Like duckweed, it grows very quickly, using its submarine roots to extract nutrients from its surroundings; and like duck weed, it forms a green carpet on top of the water. But there the similarities end. It produces rosettes of leaves, often attractively pleated, up to six inches in diameter which spread out when there is sufficient room but which grow upright when packed together. Emerald green in hue, these neat rosettes look better in a confined space – a water jar or ceramic bowl. Pistia propagates itself by offshoots from the mother plant and does best in full sun.
More unusual is the water chestnut (trapa bicornis), although we are familiar with the nutty fruits which come from its dark brown submerged root system. For this reason, it is cultivated commercially, especially in China,. But the actual green plant is less in evidence, though it is sometimes seen decorating ceramic pots outside Thai restaurants or spas in Phuket. What makes it distinctive is the leaves: they are flat and diamond shaped and form an ornamental and symmetrical pattern on the surface of the water. They can be grown from fresh fruits submerged in water, but unlike the water lettuce, germination is slow. Worth the wait.
There are no comparable issues with the water hyacinth (eichornia crassipes): it grows at such a rate of knots that it can quickly clog waterways – as it has done in Phuket Town. The plant has also taken over a lake in Rawai, with the result that the actual lake has become invisible. One to avoid ? Well, it needs watching and is not suitable for small containers. On the other hand, it produces thick fleshy green leaves and prominent hollow stalks of dramatic mauve flowers that superficially resemble those of the land-lubber hyacinth. Like the rest of these floaters – and the hyacinth has submerged, free floating roots – it likes full sun, and spreads by means of offshoots.
Free floaters that never break surface include several plants that quietly carry on with their existence below the surface – generally ideal for aquaria and for ponds. One of these is ceratophyllum, a delicate plant with fine, dill-like foliage which encircles its narrow stems. Another is elodea or Canadian pond weed. Though these look decorative in glass fish tanks, they provide no visual stimulus in ponds. But undoubtedly they have their uses ; they both help oxygenate stagnant water, and provide cover for small fry and the eggs which will one day spawn a new generation of fish .
green galoshes 