Choosing A Tree For Your Garden
Planting trees in gardens is not merely an aesthetic consideration, one should also muse over the wider issues of suitability both in the shorter and longer term.
Tree related subsidence is not a usual occurance in the North West of England due to higher levels of rainfall and lesser amounts of shrinkable clay soils. However, it is still an issue that should be considered before planting trees in built up areas.
British Standard 5837:2005 Trees in Relation to Construction states a recommended minimum distance for trees from buildings as 5 metres. This is a rule that should always be followed when planting new trees, however it is not an indication that trees closer than 5 metres will definitely cause damage to buildings.
Willow and poplar species are usually highly water demanding and therefore extra consideration should be given before planting these in the vicinity of buildings.
Trees do not (usually) stay the same size and shape as when they are bought. Most will grow to a very significant height, girth and crown spread, and these issues should be properly considered before selecting the species to plant in your garden. The wrong species type can not only have negative consequences for yourself, but could also adversely affect the lives of your neighbours. For instance, planting a row of leylandii trees along the boundary may seem like a good way to create some privacy but in the long term these will grow to be a burden to yourself for pruning and could cause serious tensions with neighbours.
Characteristics to consider include:
- Crown density (sycamores have very dense crowns, birch allow through dappled light)
- Height (some species of poplar can grow up to 40 metres, with most apple trees not growing taller than 5 metres)
- Crown spread (some species of oak tend to grow very wide and can be as wide as they are tall)
- Root spread (the generally accepted rule of thumb is that tree roots will spread for approximately 12 times the diameter of the stem at chest height – though there are always exceptions!)
- Root depth (some trees are shallow rooted, this can disrupt paving and cause problems for mowing grassy areas)
- Likelihood of splitting (ash trees have heavy foliage which is accentuated in wet windy weather, they are therefore likely to have limbs fall more often than other species)
Are there underground services in the vicinity of planting? It is advisable not to plant any trees within a metre of underground pipes as when the tree grows the weight can cause the pipes to crack. It is also possible that pipes in the immediate vicinity of trees could be damaged by roots growing beneath them and then expanding, lifting the pipe and causing cracking. This is less likely with modern pipework but it is better to take precautions in order to avoid the potential of costly mistakes.
Are there overground services above the planting location? If the answer is yes then you are either limited to a species that will maintain a smaller mature height, or you need to choose an alternative planting location.
Will large leaves or fruit be an issue making footpaths/driveways slippery? If yes, consider trees without fruit and/or with smaller growing leaves, or perhaps a tree with needles instead of leaves.
Is your soil deep enough to sustain a tree healthily and safely? The gardens of newer housing developments can often be a relatively thin layer of top soil placed on top of rubble from a previous site development. Check the depth either with a metal rod, or by digging a test area. Depending on tree species at least a half metre depth of soil is a necessity.
Will the tree grow and block lighting (either your own security lighting, or street lighting)? If yes, the tree would require regular and probably excessive pruning which will cause potential safety issues in the future (not to mention making an ugly tree).
Trees are always strongest and most impressive in their natural form, pruning can solve issues where there has been storm damage but otherwise pruning should be considered a last resort. Choosing the correct tree for the planting location should mean that pruning will never be a required.