If a small amount of space is available a very pleasant addition to the garden would be a garden pool, in which it will be possible to plant water-and other . Never, however, be tempted to install a pool under overhanging trees as the falling leaves will always present a problem.
Decorative fish can also be introduced into the pool when it has become established, and these need little attention apart from feeding and even this is infrequent.
Pools may either be constructed with concrete on the site or as pre-formed shapes made of fibreglass which simply need a suitable sized hole excavated for them. Another method of preparing a pool is by taking out theto the required size and lining the whole area with a double thickness of polythene sheeting, which is available in widths up to 12 feet. This sheeting can be bought in either blue or black and although it may not be quite so indestructable as the two earlier types of pool, it is certainly considerably less expensive and lends itself to use when small irregular shaped pools are required.
The first decision to take when preparing the pool is its shape. In a formal garden a rectangular or round one may suit the layout better than an irregular one which should be more suited to a rockery or informal garden. Whatever shape the pool is to be, the size must also be considered and remember here that even with a polythene or fibreglass pool the hole still has to be excavated and it is surprising just how much soil has to be removed to accommodate even the smallest pools. While these decisions are being made and before any purchasing begins it should be mentioned that there are many plants that, although not true, like to grow in shallow water and provision is often made in pre-formed pools by the addition of a shelf or shallow edge round the sides. This is well worth having even at a little more expense, as many marginal plants are most attractive and will help to make the pool look as natural as possible.
Pre-formed Fibreglass Pools
Preparations for sinking a fibreglass pool are simply a matter of digging out the required space to allow the pool to be sunk in easily after checking that the site is level. This can of course be regulated later by propping up the pool and re-checking the level with a straight board placed across the top of the pool and a spirit level. This must of course be done before the water is added.
When the pool is finally in position soil should be packed into the excess space round the sides and the plastic top edges concealed with crazy paving or paving stones.
Polythene Lined Pools
After the ground has been levelled and excavated for the required size, a thick layer of either peat or sand should be spread over the soil to act as a protection against stones or other sharp substances which might puncture the sheeting.
When this has been done the plastic can be arranged into the hole so that when pushed down completely into the bottom there will be an overlap at the top edges of at least 9 inches which can again be concealed with paving stones.
Make sure when preparing for a concrete pool that it will finish up being level as, unlike the two earlier types, once it is concreted it is permanent and will not be so attractive if the water level does not match the level of the pool itself.
When the level has been checked and the pool is ready to be excavated remember to dig it in varying depths to accommodate the various types of plants, and shallow enough for the concreting to be done without the need for shuttering.
When mixing the concrete try to do this as near to the site as possible and work at a rate of 2 parts sand, 1 part cement and 3 parts coarse aggregate. A waterproofing agent should also be included which can be purchased from the builder’s merchant when the other supplies are ordered. This must be added according to the instructions.
The mixture although workable, must not be too sloppy and should be laid to a thickness of 4—5 inches. If it is thought necessary a layer of wire netting can be placed into the hole as reinforcement beforehand.
For the first week after concreting has been finished the pool should be kept covered in wet sacking. After this time has passed the sacking may be removed and the pool partially filled with water, after which more water can be added daily until the pool has been completely filled.
Every two weeks the pool should be emptied, scrubbed and re-filled until at least six weeks have elapsed when it can be finally filled. The cement should now have become well seasoned and in a suitable condition for planting up.
Apart from the aerating plants which are necessary and must be added to the completed pool to keep the water fresh and in good condition, also remember the water lilies which should be planted in May or June when the water has warmed up sufficiently. These may be planted into baskets which can be supplied with the lilies and filled with fairly heavy soil which will stay firmly packed together when placed into the water. The baskets must be weighted and lowered gently into the deepest part of the pool.
When ordering water lilies, and indeed all other aquatic and marginal plants, it would be wise to consult a nursery specialising in these, who will be only too pleased to give advice on what is needed for your particular size of pool and in some cases supply a carefully balanced selection of plants to suit it.
If the pool shape has been chosen to incorporate a shelf of shallow water at the edge it can be planted with such plants askaempferi and Iris laevigate, both of which flower during the summer and like being grown in shallow water.
In the area surrounding the pool, and particularly when drainage pipes have been laid to divert excess water from other parts of the garden, a bog garden may be planted and for this there is a very wide range of delightful plants which grow well in damp conditions. Even if the soil is not naturally wet it is quite possible to flood the area artificially from time to time to imitate the right conditions. Into this area plant Marsh Marigolds and varieties of Hosta and Trollius.
Fish for the Pool
There are many different kinds of goldfish, shubunkins and other fish which are quite suitable for adding to the pool. These should be fed only during the early spring, summer and autumn as, during the winter there should be sufficient food available in a well stocked pool. It is very dangerous to over-feed fish.
It will also be beneficial to the pool if a few water snails are included when stocking the pool which will help to keep away the green slimy matter known as algae. This green growth is a condition which occurs mainly in newly planted pools and is usually a result of both insufficient oxygenating plants and shade. To a large extent this trouble is caused by the water’s exposure to strong sunlight and when the pool has been able to grow enough freshening plants and surface leaves for shade the trouble should clear up.