Water Features – Water Gardening Ideas
This brings us to water features and water garden ponds made from ‘found’ containers. Here the choice is endless. From baths at one end of the scale to an upturned dustbin lid at the other, almost any container can be adapted for use in . Some can be left above ground but they can also be sunk into the ground to look like a normal pool. Once again, they will look better if they are given a coat of black waterproof paint or sealant. If they arc not absolutely sound, they could still provide a strong base for some black polythene sheeting.
However, like all water garden ponds, they should be at least 45cm (18″) deep if you intend to keepin them, or grow any but the pigmy Waterlilies. If, on the other hand, you are content to use them as mere mirror pools, just a few inches of water will do. You will have to be prepared to empty them and clean them out regularly, as they will be subject to rapid colonisation by algae, the water becoming green and possibly filled with blanket-weed. Shallow water heats up rapidly and this – as well as exposure to light – favours algal growth. A shade pool will probably remain clear a little longer. There is, in any case,a certain attraction about green water, especially in small town gardens; it looks cool and mysterious. If these shallow containers are merely sunk into the ground and not fixed in by mortar, they will be easy enough to remove for emptying and cleaning purposes
There was an attractive mirror-pool on show at Chelsea Flower Show one year, lined with slate slabs and bordered with granite setts. Unless you live in a slate-mining area, you are unlikely to obtain such slabs cheaply but you might find the odd large slab lying around, left over from the roof of the outside toilet maybe. If you found one or two of these you could get some of them cut to form the side walls and then use the largest piece for the base. You might make a mock-up of this scheme by pressing old roofing slates into wet cement, or use some black quarry tiles instead. The cement could be coloured black by a special stainer.
Any cement that is used in a water garden pond intended for fish or plants will have to be ‘cured’ or sealed in some way before use, as lime leaches out of fresh cement and is poisonous to pond life. If you make the pool in the autumn, fill and leave it until the spring before emptying and refilling, it should be safe enough. Few of us, however, are so patient. The pool can be filled, left for a few days and then emptied. This will have to be repeated several times.
I have heard of a method whereby a solution of permanganate of potash, strong enough to turn the pool water to the colour of a good red wine, is left in the pool for several days and then the pool is emptied and filled with clean water. There are also various sealers now available at water garden centres. All this will apply equally to any cement you introduce into the pool after construction, for example concrete blocks to hold or anchor plants, and to the cement that holds the coping in place, even if it is above the water line; with heavy rainfall, or if the pool is accidentally overfilled when topping-up, it could still come into contact with the water.
For a deep pool, you could use baths, sinks, water tanks and cisterns plasterer’s mixing trays, tin trunks, all sorts of metal, ceramic and plastic utensils and containers. Anything, in fact, which is watertight or can be made so by paint, liners or sealants, and has a minimum depth of 45cm (18″), with a minimum surface area of about 0.36 square metres (4 square feet); for example, a pool 60 x 60cm (2′ x 2′) will support a small Lily, some oxygenators and a couple of fish. The usual calculation for the number of fish a small pond can sustain is one fish to each 0.28 square metres (3 square feet) of surface area. Overcrowding can lead to disease.
The larger sized containers can also be used as water butts connected to the downpipes from the guttering, they will he useful back-up system for the garden; the water can be can be used to keep the pools full without the sudden lowering of the water temperature which comes from filling them from a tap (this affects the balance of the pool life), for watering plants that are intolerant of lime and for bringing on new water-plants until they are ready to go into the larger pool. A lot of plants are happier when sprinkled with this warmer water, rather than having to face the short sharp shock of tap-water.
Old casks and barrels make good sunken water garden ponds; on a sloping site you could place a series of them, one beneath the other, down the slope, sunk to their rims and, once again, framed by logs, pebbles and plants. The top one can be filled up from time to time and allowed to overflow into those below, if there is no natural flow to do this for you. The larger and deeper the cask the better. They must be cleaned out thoroughly and, if necessary, sealed.