?Stopping Erosion in the Garden

There is world-wide anxiety about the great loss of fertile land due to erosion which is apt, mistakenly, to be considered only a concern of the Governments and farmers involved. Gardeners, particularly in the tropics, lose a lot of good topsoil each year, because they do not take a few simple precautions. The following suggestions are made as the result of practical experience. It is wasted effort to improve the soil, only to lose its fertility through erosion and leaching. Paths and drives probably contribute more to erosion than any other part of the garden. They represent quite a large area, which is usually carefully weeded, thus allowing rain water to collect and rush away unhindered. You probably prefer your paths to be free of weeds, but why not have a shallow drain on either side covered with a low- spreading grass? If this is properly tended and cut it will not look untidy and it will certainly minimize the amount of topsoil which can be swept away. Alternatively, the paths can he raised above the level of the surrounding garden; they will not become muddy, and if properly grassed down can become part of the pattern of the garden. Drives certainly do present more of a problem as many are curved and easily churned up by car tyres. Here the answer is to take note of the direction of the flow of water during a heavy rainstorm and at strategic places, where the flow is greatest, place flat stones or odd pieces of concrete. These barriers will decrease the speed of the flow and trap the particles of soil in the spaces between the stones, where grass can then be planted.

Generally, guttering is not fitted to the eaves of houses because of the fear of providing breeding places for mosquitoes, and the rain drips down to the ground. This drip line in time becomes a drain which gets wider with each rainy season. One remedy is to plant the drip line with ferns or bulbs of the lovely Crinum natans. Both will accept a terrific amount of water without damage, and during the rains the foliage will prevent any flow of water from forming gullies. If planting is not desirable, then a stone-bottomed drain will also prevent gullies from being formed.

In the garden itself, the value of mulching cannot be over-stressed. Heavily mulched beds will cut erosion to a minimum, but it must be a continual process as in the tropics grass mulch breaks down very rapidly and. needs continual replacement.

The terracing of slopes is a costly business and one that many gardeners will not be able to afford, but as a long-term project it will pay handsome dividends. One very badly eroded slope well known to the author was brought back to a semblance of fertility by the construction of simple contour bunds. The land now supports a variety of shrubs and trees with a good sward of grass.

To stop erosion it is essential to cover the land. For permanency grass is best, but otherwise all newly-cultivated land should be covered with mulch immediately.