While it is difficult to eliminate an annoying noise completely, it is possible to use plants to filter it down to a more acceptable level. Plants near the house look much more attractive than sound-proofing.
Hedges as Screening
The one thing it is difficult to get away from in a built-up area is noise - it is constant, from traffic, trains, aircraft, people and so on. To a large extent, noise becomes so familiar that it barely registers, but there are occasions when it is preferable to do something about it. At the front of a house, a particularly persistent noise may interfere with sleeping, for instance, and here it may be useful to install plants to act as a baffle to the noise and to try to deflect it up over the building.
Hedges, particularly when they consist of broad-leaved evergreen plants such as Prunus laurocerasus, Aucuba japonica or FJaeagmis x ebbingei, are effective at reducing noise, because they form a dense barrier throughout the year. The higher the hedge, the higher it will deflect the noise.
In a very small garden, this may not be an option, because hedges do take up quite a lot of space, so the strategic positioning of a single upright or small-sized tree may be necessary Both Prunus 'Amanogawa' (upright) and Prunus x subhirtella Autumnal is' (a small tree bearing flowers throughout the autumn and winter) are deciduous trees suitable for small gardens.
Planting a Hedge
Image Source: http://www.scrooby.net/page/environment
1. Mark out the line of the hedge with a string and canes. Use a spade to dig holes deep enough to accommodate the plants' roots, allowing space for the intended thickness of the hedge. For each hole, place the rootball against the side of the hole, and cover with soil.
2. Firm the soil gently with your foot. Repeat until the whole row has been planted; then apply a dressing of fertilizer on to the soil surface around the young plants and fork this into the top 5cm (2in) of soil.
3. Water the plants in well, then add a layer of organic matter 10cm (4in) deep as a mulch over the soil surface, to retain moisture and suppress weeds.
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