Ditches and marshy areas are valuable for wildlife. They don’t have the same appeal as ponds, but on the other hand are less likely to attract vandalism.
Existing ditches should normally be managed to maintain a range of habitat types, including mud and shingle banks, tall marginal vegetation, scrub and trees. Old overhanging trees with extensive root systems are particularly valuable in forming ‘undercut’ features. The banks of ditches can be scythed or mown on a rotational basis, always leaving some uncut areas. Strips from the top of the bank down to the base of the ditch can be left to maintain the range of habitat types.
Existing marshy areas should need little attention, except for the removal of encroaching scrub or seedling trees as necessary. Annual mowing must be continued if this has been the traditional method of management.
On ground with a high water table, ditches and scrapes can be created by simply excavating the ground. Avoid digging anything which will act as a drain and take water away from the site. A ditch can have two ‘blind’ ends, so holding water in the winter, and drying out in the summer. A scrape is a shallow hollow which is seasonally wet. Ditches and scrapes should have gently sloping sides.
On well drained soil, ditches or marshy areas can only be created by using a liner, similar to a pond lining. In addition to rainfall, an extra water supply will be needed to keep the site sufficiently damp. Consider using rainfall collected from roofs, piped to the ditch or marsh.
Backfill marshy areas with the soil excavated to create the marsh. Invert the soil, so that the original surface soil, containing the majority of weed seeds, is buried at the bottom. Plant up with marsh and bankside plants, planted at about 300mm spacing if possible, so cover is established quickly and unwanted plants suppressed. Seed mixes suitable for damp ground are available from wildflower seed specialists. These can be propagated in trays and pots for planting out, or sown direct. Weed out docks, nettles, thistles and tree seedlings as soon as you notice them. Scythe or mow the vegetation in late summer.
Reedbeds
Reedbeds, comprised mainly of common reed, with common clubrush, reedmace, reed grass and other plants, have the ability to filter out solid waste and pollutants. Reedbeds for water treatment are being constructed in many parts of the Uk and elsewhere, for the treatment of sewage waste, industrial waste, farm waste, and run-off from roads and other hard surfaces. Local authorities and water authorities are becoming increasingly interested in this system of water treatment, which also creates valuable and attractive areas for wildlife.
On the domestic scale, reedbeds can be constructed for purifying ‘grey’ water from sinks, baths and washing machines. The water can be used for garden irrigation, or fed into a pond before returning to the drainage system as necessary. This creates a valuable habitat, and decreases the pollution load entering the drainage system. For further details see Waterways and Wetlands – Wetlands for water treatment. The Centre for Alternative Technology publish a range of booklets and other publications on reedbeds for treatment of sewage and grey water.
