Читать книгу The Wildlife-friendly Garden - Michael Chinery - Страница 20
ОглавлениеIf you have room to create only one semi-natural habitat in your garden, then I think it should be a garden pond. This is one of the richest of all habitats in terms of wildlife. As well as providing homes for frogs, newts, dragonflies and many other exciting creatures, it provides food, drink and bathing facilities for birds and assorted mammals. And all will give you, the gardener, a great deal of fun.
If you are really lucky your garden might already have a stream that you can dam to make a small pond. Local rocks can be used to form the dam, or you can utilize a tree trunk. Oak and elm are good for this as both timbers survive well under water. A height of about 50cm (20in) is fine for the dam. Be sure to consult the appropriate authorities if you want to create a larger pool because anything more than a small dam could interfere with water supplies further downstream.
Most of us have to create our ponds from scratch, but this is not difficult if there are strong people to do the digging. Pond plants and animals like plenty of sunshine, so don’t site your pond under trees. Apart from creating a lot of shade, they will drop their leaves into the water in the autumn and cause a lot of problems. If you compare a woodland pool with one in the open, you will be in no doubt that the latter is a much richer and more attractive habitat.
Acres Wild/Ian Smith
Surrounded by a rich variety of wild and cultivated marginal plants, including yellow irises and brilliant orange primulas, this pond will attract a wide range of insects and other wildlife, and there is enough open water to encourage frogs and dragonflies to come and lay their eggs.
Constructing the pond
Ponds dug in low-lying areas where the water table is close to the surface sometimes fill themselves, and you can’t ask for much more natural ponds than these. Otherwise you will have to line your pond.
Preformed fibreglass liner
If you decide on a preformed fibreglass liner, all you have to do is to buy one of the shape and size that you want, dig a similarly-shaped hole, and drop the liner into it (see). A morning’s work can give you a very attractive pond!
Acres Wild
Acres Wild/Ian Smith
This cross-section of a pre-formed fibreglass pond shows the correct level for a shelf for marginal plants. The surrounding paving stones must be firmly cemented into place and should overhang the edge sufficiently to conceal the edges of the pond liner. Frogs may shelter under these overhangs, but you need to provide one or more stepping stones so that the animals can get out of the pond.
Acres Wild/Ian Smith
1 Mark the position of the pond with pegs and string or a line of sand for irregular shapes.
Acres Wild/Ian Smith
2 The excavation must match the profile of the unit. Measure all depths carefully from the rim.
Acres Wild/Ian Smith
3 Allow for installation of the pool and back-filling by digging out a larger hole than marked.
Acres Wild/Ian Smith
4 After removing all stones, make sure that the ground is compacted down.
Acres Wild/Ian Smith
5 Smooth the sides and spread a 5cm (2in) protective layer of sand on the base and sides.
Acres Wild/Ian Smith
6 Press the unit gently until level, then part-fill with water and back-fill with sifted soil or sand.
Flexible liners
These liners allow you to have a pond of virtually any shape you like. You can use heavy-duty black polythene, but butyl rubber is a better material and, although considerably more expensive, it is likely to last much longer. Whatever you get, make sure it has at least a ten-year guarantee.
Calculating the liner size
You can calculate the required liner size by measuring the maximum length and breadth of the pond, adding twice the maximum depth to each dimension, and then adding a further 50cm (20in) to each to allow for sufficient overlap at the pond’s margins. Although you can choose whatever shape you like, butyl rubber liners are usually rectangular, so long, narrow ponds tend to be rather wasteful of this lining material.
WHICH WATER SOURCE?
The tap is usually the only source of water for the pond. The high mineral content of tap water may encourage the algae to multiply rapidly and turn the water green in the summer, but this will not harm the wildlife of the pond and the algae will gradually dwindle as they use up the minerals. The best thing, if you are planning to have a pond, is to store up a supply of rain water ready for filling it. Always use rain water to top up your pond in the summer: an adaptor fitted to a drainpipe can be used to divert water into a hose leading to the pond.
Acres Wild
A) Moisture-loving shrubs, such as guelder rose and alder buckthorn, can be planted around the pond, but do not let them shade the water
B) Free-floating plants, such as frogbit, provide shade for many small animals
C) The floating leaves of yellow water lily and similar plants make good landing pads for dragonflies
D) Large stones breaking the surface provide perches for drinking birds and basking spots for frogs
E) A sloping ‘beach’ makes it easy for animals to get in and out of the pond
F) Wetland plants, such as marsh marigold, provide food and shelter for insects and many other small creatures
G) The flexible liner can be covered with fine soil here and there to allow plants to root naturally
H) Submerged plants, such as curled pondweed and water milfoil, maintain oxygen levels
I) The jetty can be supported on building blocks, but these should be set on rubber or plastic pads to protect the liner
J) Native marginal plants, such as arrowhead and flowering rush, can be planted in the swampy area at the edge. They give a natural effect and provide cover for many animals
PROTECT YOUR LINER
Before installing the liner, remove any sharp stones that you can see and then line the hole with soft sand to protect the liner. You can also buy polyester matting specifically made for this purpose. Alternatively, you can use old plastic bags, as used for potting compost, but an old carpet is even better.
Acres Wild/Ian Smith
1 Decide on the shape and size of your pond and mark it out with a rope or a hose-pipe before you begin digging. Make the pond as big as you can, but ensure that you can get a liner of a suitable size before you start work!
Acres Wild/Ian Smith
2 Make sure that the edges of the pond are perfectly level, otherwise the liner will be exposed in some places. The central area should be at least 50cm (20in) deep to ensure that the whole pond does not freeze solid in a hard winter.
Acres Wild/Ian Smith
3 It is best to start digging in the centre and then slope the bottom gently up to the surface. Leave a flat shelf about 15cm (6in) below the final water surface on one side, so you can grow marginal plants there in pots (see here).
Acres Wild/Ian Smith
4 It’s now time to install the liner by spreading it over the hole and pushing it roughly into position. Weight the edges down with something heavy, ensuring that there is at least 25cm (10in) overlap all round the margin. Then you can start adding the water. As it runs in, the weight of the water stretches the liner and moulds it to the shape of the hole.
