The Water Garden – Ponds and Caring for Them
The cool and tranquil sight of a still pool or the cheering sound of bubbling and cascading water both add an extra dimension to the garden.
Recollections of green, stagnant water and a leaf-covered surface should be dismissed – clear water is only a matter of management, and of careful siting.
A water garden pool is not only a feature in its own right, but home for many lovely plants. Besides the deep-watersuch as waterlilies and water hawthorn, there are choice plants for the margins and pond surrounds.
Once a water garden pond has been constructed and planted, little further work is required, and it can form a natural and relatively maintenance-free part of the garden. But as with all things, planning and a few sensible precautions can make all the difference.
Siting a Pond
Pools, which constitute the most important part of a water garden, need careful siting if they are not to become a perennial source of disappointment. The plants that live in them waterlilies, marginal aquatics and the like require abundant sunshine to flower, so avoid shady places near tall buildings or areas with overhanging trees. The latter present a further problem on account of their leaves, since one of the major causes of discoloured water and fish mortality is too much organic material in the water. As this decomposes it releases mineral salts which in turn encourage various forms of algae or even methane gas in very bad cases.
Site the pool right out in the open; either as a formal feature with a paved or grass surround or as an integral part of a larger feature. It can, for instance, be teamed with a, perhaps including a stream and waterfall, or be combined with bog plants in an informal setting. Marginal aquatics can be included to disguise the pool edges and to provide extra colour and interest.
Keeping the Water Clean
Unless the water is clear, it loses much of its appeal, and it is difficult to see the fish. All water garden ponds become slightly green or cloudy in spring, mainly because of activity by the small animal occupants, which stirs up the mud. However, this state of affairs usually adjusts itself in a week or two as plant growth becomes stronger. Natural shade, such as that provided by waterlily leaves and underwater vegetation, is the greatest deterrent to algae, which must have light and food in order to thrive. Submerged oxygenators utilize most of the mineral salts released by decaying vegetation, fish excreta and the like, and in the process of growth combine water and carbon dioxide exhaled by the fish. This results in a certain quantity of oxygen being returned to the water, which in turn is utilized by the fish. Thus the two work together and the secret of striking a balance is to have plenty of submerged vegetation, some floating leaves or plants to cast some shade, and the correct types of fish.
There are chemicals which can be added to water to clear algae, but the results tend to be only temporary, and the addition of chemicals changes the nature of the water. This may not matter in a lake or large pond, but can have significance in a small pool. For this reason natural means of keeping down algae are best – pulling out the coarser types with the hands, using a garden rake or twisting a pointed stick in the centre of the mass – and the other kinds by netting and planting more oxygenators and floaters. Some of the latter however like duckweed should never be purposely added as they are extremely difficult to eradicate later. If inadvertently introduced, use a hose to drive the offending plants to one corner and then scoop them out with a large net.
Planting and Maintenance
Five types of plants are commonly used in water garden ponds. The deep water ornamentals like waterlilies and water hawthorns have submerged roots but their leaves and flowers float or rise just above the surface. Plant these in baskets of heavy, fibre-free loam with a little added bonemeal, and topdress this with 2.5cm (1 in) of clean pea-sized shingle. Gently lower the baskets into the water, propping them on bricks for a time until new growth appears, then set them at the correct depth for their type and size.
Marginal aquatics have submerged roots but emergent flowers and foliage. These need shallow water of about 5 – 15cm (2- 6 in) depth, and a plain loam. They may be planted in pond-side pockets or in pots or baskets.
Oxygenators such as elodea live entirely submerged and most are almost roofless, so plant these by gently clipping a thin strip of lead round the base of several stems and drop the bunches into the pool.
Floaters are installed in seconds (just place them on the water’s surface), but bog plants such as waterside primulas require soil that is always moist but never waterlogged. They also need richer, so incorporate some leaf-mould, peat or garden compost.
Maintenance of water garden ponds consists of cutting back dead foliage in autumn; dredging out fallen leaves; keeping the pool full of water at all times andand clearing out occasionally. All planting operations are best carried out in spring.
Stocking with Fish
Fish are the only essential animals required. They are necessary to keep down mosquito larvae and other pests; they also bring movement and colour to the pool. Avoid bottom-of-the-pond dwellers such as carp and tench, which continually stir up mud, and also avoid pugnacious kinds like sunfish and sticklebacks. The best kinds for small pools are goldfish and golden orfe.
Contrary to common belief, water snails and other creatures are not necessary and indeed may become a nuisance by eating or disfiguring the plants.
Accessories for Water Garden Ponds
Most specialist water garden stockists offer a varied range of accessories to help make water garden ponds more attractive or easier to manage. They include water-lily baskets (plastic, with holes round the sides), fountains and simulated streams, cascades and waterfalls, and pumps to keep these moving and to recycle the water. Other pumps will empty the pool when necessary, and there are heaters to prevent the water freezing in winter. Thermometers, hand nets and various ornaments are also available.