Gardener's Corner
May 2003
All about pond
When a pond becomes overgrown or dull, it is advisable to carry out a major clean up. This will provide the opportunity to control the plants' growth by dividing or thinning where necessary. Small ponds require attention every four to five years. Late spring is the best time to clean out a pond, allowing time for plants to re-establish over the summer.
1. If the pond has a submersible pump, you can drain the pond by disconnecting the delivery pipe and connecting a hose in its place: otherwise, start to siphon away the water. If the pond contains fish, remove just enough water at first to make it easier to catch them. Fill a holding container for fish with the original pond water.
2. Remove containerised plants from the margins of the pond; integral-planting beds need not be disturbed, unless plants need dividing. Wrap planting crates in wet newspaper and place in a shady area. Water the plants and wet newspaper every few hours.
3. Catch as many fish as are visible with a net and bowl and place them in the holding container in the shade. Remove containerised deep-water plants and water lilies, wrap the containers in wet newspaper, and place them with the marginals. Remove floating plants and oxygenators, retaining a few bunches of each in a bucket of water.
4. Remove any decaying plant matter that may be concealing more fish. Trawl the net through the water to catch any remaining fish. Place them in the holding container and cover with a net or wet towel. Switch of pump and remove it. If the pump requires some attention, it is best carried out before you place it back into the clean pond.
5. Use a plastic bucket to remove the remaining water. Check the bucket for any beneficial creatures, such as frogs, and place them in the holding container. The water from the pond can be used on adjacent borders - do not pour down the drain, as it will clog up with silt traps.
6. Scoop put the mud with a dustpan. Taking cares not to damage the lining or brick base. Reserve a small amount of mud and water in a bucket to help reacclimatize the fish when releasing them into the clean pond. The remaining mud can be added to compost.
7. With the pond now empty of fish, plants and most of the mud, add a little water and brush away any remaining algae, mud, or plant debris. Then bail or siphons out the dirty water. Inspect the surface of the lining or base for damage and carry out any repairs.
8. Partially refill the pond to a depth that will allow you to stand in the water in rubber boots or waders. Unwrap the water lilies and other deep-water plants. Divide them and trim them in order to remove any damaged stems and foliage.
9. Submerge the water plants in the deeper area of the pond. Any new, small plants should initially be placed on stacks of bricks. Position ornamental plants such as water lilies first, then add oxygenating and submerged plants.
10. One the deep-water plants have been installed adds the bucket of reserved mud and original water. This will help any fish and other pond life to establish them quickly when put back in the pond.
11. Before transferring the fish from the bucket into the pond, examine them carefully. Check that they have not been damaged in any way, and look for sign of fungal growth or other disorders. Then reintroduce them to the pond.
12. Unwrap the marginals, and divide or thin them out, if necessary. Then replace them in their planting baskets on the marginal shelves. Having done this, you can then refill the pond to its correct level. Reconnect and position the pump.
Your original pump does not work effectively; this is more than likely due to the amount of silt built up. You may find that once the pond has been cleaned the pump works more effectively, otherwise you might have to invest in a new pump. There are many types of pumps, assess what you want it to do and consult a specialist with your requirements. The Royal Horticultural Society has a very good book on 'Water Gardening', by Peter Robinson. I hope that you find the information in this letter of beneficial.
In order to develop and maintain a healthy environment within a pond, it is vital to have some submerged plants and floating leaved plants, whose role is to filter and oxygenate the water and, by competing successfully for sunlight and nutrients, so minimize algal growth in the water. It occurs in high light conditions when a pool has inadequate surface cover, both in new ponds and each spring. To help this process, third to half of the pond's surface should be covered by the leaves of free-floating and deep-water plants. In established ponds, water lilies are especially important, since they are among the first plants to spread their leaves in spring. Free-floating plants are especially useful in early establishment of a new pond, or in prolonged hot, sunny weather.
Oxygenating Weed: an adequate quantity of submerged plants such as Lagarosiphon major should be added to new ponds, so that their leaves may begin to produce oxygen that will aerate the water and enable a healthy ecosystem to develop.
Fast growing floating plants: small free-floating plants such as Azolla filiculoides spread rapidly, and are extremely useful for providing initial cover. By mid - summer, they will probably need thinning so that the surface cover is not too dense.
Consolidating wet ground: if your pond has boggy surrounds, plants with creeping, mat-forming root systems, such as Houttuynia cordata, Carex, and Persicaria will soon grow to hold soil together and reduce surface evaporation.
Water will always attract wildlife, birds, insects, amphibians, or mammals. Careful planning is fundamental: plants should be chosen those not only sustain the water's ecosystem, but also provide cover and food. Native plants and flowers are usually more attractive to indigenous wildlife.
First make sure the pond has a good variation in depth so that several different habitats that may support a wide range of plants and animals. The deep areas of the pond should be at least 45cm (18in), and preferably 90cm (36in), in depth. The sides of the pond should be gently sloping; both sunny areas and cool shade around the edges of the pond are important.
Floating leaves; deep-water aquatics provide vital shade, and large, flat leaves also make landing pads for insects. Nymphoides peltata and Nuphar are less formal-looking alternatives to water lilies for naturalistic settings.
Nook and crannies: evergreen and semi-evergreen grasses and sedges such as Carex and Schoenoplectus provide cover at the edge of the water throughout the year. Many are preferred foods of the water vole, which, unlike the fierce shrew, is vegetarian.
Food for fowl: duckweed (Lemna trisulca) and duck potato (Sagittaria latifolia) is so called because they are the favourite food of the duck.
Water quality: submerged plants keep the oxygen level sufficiently high to support insect larvae, such as those of the dragonfly, that live under pebbles on the bottom of the pond.
Pebble beach: a gentle slope ensures that amphibians, small mammals, and bathing birds can approach the water safely.
Lagarosiphon Major: submerged plants play a practical role, releasing oxygen directly into the water, and also shelter fish fry and other tiny creatures.
Basking places: rocks placed in the sun and shelter near the water provides resting and sunning areas for small amphibians.
Seed producers; plants that freely produce seed are valuable food sources for fauna.
Predators: be prepared for the arrival of predators; herons can wipe out fish and amphibian populations. Domestic cats may also develop a taste for hunting.
Native flowers: choose wildflowers species rather than highly bred cultivars; loosestrife (Lythrum), meadowsweet (Filipendula), and Joe Pye weed (Eupatorium) are more appealing to indigenous creatures.
Clumps of cover: shyer birds such as moorhens and warblers appreciate clumps of reeds, rushes, and aquatic irises.
Butomus umbellatus: the flowers of this rush attract pollinating insects, while the roots are a food source for small animals.
Butterfly bush: no wildlife garden or pond should be without Buddleja, beloved of bees and butterflies.
Acer Campestre: plenty of cover with waterside plants, shrubs, and trees reassures creatures that they may approach in safety. Taller trees provide safe havens in which birds may nest.
Native trees: the abundant flowers of hawthorn (Cartages) and, elder (Sambucus) attract insects, while the fruits that follow provide food for birds.
Ranunculus Lingua: yellow flowers attract many winged insects.
Insect-eaters: creatures that hunt on the wing, such as house martins, swallows, and bats, are attracted wherever there are abundant flying insects.
Salix Caprea: willows are useful for moths and butterflies; several types of caterpillar feed on them.
Digitalis Purpurea: the flower spires of the foxgloves are magnets for bumblebees.
Small marginals: grade plants by size, from trees to small marginals, right down to the water's edge to provide continuous cover. Plants with mat-forming roots, such as water forget-me-not (Myosotis scorpides), spread well along the water's edge.
Ruthe Gray