Organic Gardening – Habitats: Ponds
Habitats : Ponds
When planning an organic garden you should introduce features that will encourage a good variety of wildlife, from birds and butterflies down to tiny insects. This may seem of dubious value, but relatively few creatures actually damage plants, and they all have their own natural enemies. By building up a wildlife community in the garden you will establish a balanced environment in which pests are less likely to get out of hand.
This does not mean that the whole garden has to look like a nature reserve. Features such as a pond, a hedge, a mixed border, a dry stone wall or a wild-flower meadow will significantly boost the garden’s value to wildlife without making it untidy and will make it more attractive for you, too.
A watery habitat
Consider putting a pond in your garden if it is at all feasible. It guarantees an influx of new creatures — those that live permanently in the water and those such as toads, frogs and newts that need ponds to breed. In addition it will attract passing animals, birds and insects needing to drink or bathe. A pond designed for wildlife can be ornamental too, but it must have certain characteristics.
While the pond does not have to be large, the bigger it is the more different plants and water creatures it will accommodate and the better conditions for them will be. The temperature of the water in a small pond can fluctuate considerably and can freeze solid in a hard winter. Ideally, you need a pond that is at least 60cm (2ft) deep at some point in the centre to ensure an ice-free area for pond life. The pond should have at least one shallow edge so creatures have easy access. You can create this “beach” with rocks and gravel even in an existing pond with steep sides.
Build in several shelves at different levels around the sides of the pond for a range of water plants; a shallow bog area adjacent to the pond will accommodate plants that like dampbut not standing water.
The best way to construct a wildlife pond is to use a flexible sheet liner, as this enables you to create the exact shape you want. A butyl rubber liner is more expensive than polythene or PVC but lasts much longer.
After excavating, remove any sharp sticks or stones and rake the surface smooth. This will prevent the liner from being punctured. Lay a soft underlining of sand, old carpet or polyester matting to protect the liner from sharp stones. Put the liner over the centre of the excavation and mould it into the contours of the pool, smoothing it down as you go.
Filling the pond
Put a thin layer of subsoil on the bottom of the pond and then fill it with tap water or from rainwater butts. Adding a bucket of water from an established pond will help to build up the pond community more quickly. Frogs and toads normally return to their home pond to breed, so the best way to introduce them is to beg some spawn from a neighbour in the spring, or obtain some from a wild pond through your local wildlife trust. Do not put in goldfish, as these eat frogspawn, tadpoles and insect larvae.
Planting the pond
Once the pond is full of water you can introduce a variety of plants. Mid-spring is the best time for planting, although any time in spring or summer is acceptable.
You will need several types of plants for a healthy, balanced pond.
In small ponds, it is best to grow plants in lattice-work planting baskets. This stops them spreading too far and enables you to lift and divide them more easily. The exception is floating plants, which are simply put on the water surface. Plant bog plants directly into the moist soil.
Submerged plants grow under the water. They provide hiding places for pond life and use up excess nutrients in the water, thus preventing the growth of algae such as blanketweed.
Floating plants drift on the surface. They reduce the amount of sunlight entering the water, providing shade for aquatic creatures and starving unwanted algae of light.
Deep-water plants have their roots on the pond bottom and their leaves float on the surface. They play a similar role to that of floating plants. Ideally, about one-third of the surface of a pond should be covered with foliage.
Marginal or emergent plants grow in the shallows of a pond and give good shelter for amphibians. Choose these plants to flower in succession throughout the summer to attract a variety of insects. Always grow each plant in the correct depth of water.
Bog plants grow in permanentlyground. They can be among the best plants for attracting bees and butterflies.