Pond Maintenance
A pond is not a fixed habitat. In many ways it is like a living organism itself, presenting a different face with each season.
In nature, the pond habitat with its open water will slowly change as it draws down carbon from the atmosphere into plant and animal tissue. As these organisms die back with the seasons they gradually fill the pond with a rich organic silt, until it finally evolves into a bog.
Pond maintenance is necessary to retain an open water habitat which provides optimal conditions for the native wetland wildflowers and water-loving creatures which inhabit the pond. At the same time it is important to organise maintenance activities in such a way as to minimise disturbance to pond creatures as far as possible. The aim is to maintain a habitat with plenty of open water between a good covering of plants.
Spring and summer are the seasons when the pond is at its most active. The watchword here is: do as little as possible. Only remove plants at this time if they are particularly overgrown and threatening to close up all the open water. Throughout spring and summer make sure your pond is topped up little and often. Rainwater is best; if using tap water leave it in buckets out in the open for a few days to allow the chlorine to disperse; even a small amount of chlorine can be fatal for tadpoles.
Autumn is the time to remove excess plant growth, and October probably the best month for the job. By that time frogs, newts and toads will have left the pond, although frogs may return to hibernate in pond mud later on, when the weather gets colder. Use a rake to remove plants from the water, taking care not to touch the liner. Any plants removed should be left overnight on the pondside to allow aquatic wildlife to crawl back into the water. The excess plants can then be put on the compost heap.
Over time, the deeper parts of the pond will accumulate silt. The best time to remove this is during the autumn, at the same time as you’re trimming back excess plant growth. Lift the cleaner surface water using a bucket, and store it in barrels for later return to the pond. Once down to the silt layer, it’s important to remember that the top few centimetres will be rich in invertebrate life, so skim off this top layer and again store it for return to the pond. The remainder of the silt can be removed using a bucket and a plastic scoop, taking care not to damage the liner. This fine rich black silt results from the pond drawing down organic carbon from the atmosphere, and can be spread directly onto flower beds or the vegetable patch, ready to promote new growth in the spring.
Once the bulk of the silt has been removed, the creature-rich top layer can be returned to the pond. Water needs to be poured back carefully, so as not to disturb the plants or gravel. The best way is to pour it gently from a bucket onto an area of turf or other material placed in the pond to break the flow.
