Even if your garden is quite small, you can probably manage a miniature water garden. Perhaps the inlet tap could be hidden among a few rocks built as a natural outcrop and then a little stream created toa small pool a little distance away. Let the stream take as long a course as possible, perhaps skirting a group or two of dwarf shrubs.
Having excavated as necessary, it is important that the bottom and sides of the pool be strengthened with brickbats, or other solid material, rammed firmly into the soil if it is of a light nature, in order to obtain a firm base on which to place the concrete.
It is important, too, to make the concrete of good quality materials. Portland cement, sand which should be clean, coarse and graded, together with a coarse aggregate are the three materials used. A good aggregate is crushed stone such as granite, gravel or graded ballast, although sometimes clinker and broken bricks can be used with satisfactory results. These should be mixed together in the following proportions : cement, one bucket; sand, two buckets; coarse aggregate, three buckets; water, half to three-quarter bucket. This should be mixed so that it is neither too stiff nor very wet; a handful should retain its shape when squeezed.
The floor of theis constructed first. Pegs being used to indicate the finished level. These are removed as the work proceeds; in order to obtain a good join between the walls and the floor it is advisable to leave the latter rough at this point. When the base of the pond is set, shuttering made of stout timber must be set up to make the walls, leaving about 4 to 6 in. between it and the soil in which to place the concrete. The boards must be put in firmly to prevent bulging as the concrete is placed in and, to prevent it from setting to the boards, first give them a coat of limewash. In large pools it will be necessary to reinforce the concrete, using iron rods or strong wire netting. To ensure a solid wall with no air pockets, consolidate the concrete with a shovel or piece of stout timber.
The shuttering must remain in position until the concrete is thoroughly set, which usually takes about a week. Having removed the shuttering the surfaees should be washed over with cement grout, made by mixing equal parts of sand and cement with water until they
are the consistency of thick cream, in order to make the pool absolutely watertight. A proprietary substance can be used to make even more certain. It is often desirable to have soil pockets round the edge of the pool. These are made between two walls of concrete, and being entirely surrounded thereby have no, retain moisture, and are suitable for water-side plants.
When the main constructional work is finished, the surround can be made. The most attractive finish to the pool is to place paving round the edge and slightly projecting. This will hide all irregularities in the concrete, and link the pool with the general garden design. This paving ean have small crevices left for rock plants such as dianthus and saxifrages or, in very formal lay outs, it can be left quite clear.
After constructing the pool, time must be allowed for the whole to sweeten, especially if there are to be fish in it. There are properties in newly made eement work that are deadly poison to animal life and harmful to vegetation, and which must, therefore, be removed. This is easily done by filling and emptying the pond three or four times before stocking it. As an extra precaution potassium permanganate can be added until the water is wine colour. After leaving it for three days, empty and refill with clear water. The pond should now be quite ready for stocking.
Preparations prior to planting are of great importance. If they were not made when the pool was first built empty away the water about the middle of April so that you will be ready for planting in May. Place on the bottom 6 in. of heavy, screened loam from whieh all organic fibre has been removed and mix bonemeal with it. Ram the soil down firmly or it will work loose when water is added. The aquatics should then be planted in the positions desired.
When filling the pool with water care must be taken only to increase the depth with the growth of the plants. As theincrease in length so more water can be added.
Another method of planting is to fix the plants in baskets, or to strap them between two turves and lower into the water.