Natural variation can sometimes come into play

WITH most of our garden plants you expect that the flower you have selected or the shape of leaf specific to that plant will stay true, year on year, writes TOM ATTWOOD. With most plants that is certainly the case. The exception to this is when ‘natural variation’ can sometimes come into play. You come across this when you are growing plants that have not been cultivated intensively to achieve a desired affect but with plants whose origins are in the wild. Take our humble native birch (Betula pendula) this beautiful tree can be found throughout the UK and closer to home Cumbria has some super woodlands where birch are a key feature. If you looked at the leaves, heights of tree or colour of bark then you would find that they varied in every category and this is what the term ‘natural variation’ refers to. Trees often display this most starkly because of their size and impact in the landscape but you also find this variability in small herbaceous perennials (plants that die back in the winter and re-appear in the spring). It can be the intensity (or not) of the flower colour where this really stands out and if you are working with a specific palette that has little room for variation then you might want to concentrate on specific cultivated varieties rather than the non-cultivated ‘wild origin’ plants who may well throw things off (but sometimes that can create something wonderfully unexpected!). The reason you are safer with cultivated varieties is that they are all essentially clones of the original plant by being reproduced using micro-propagation, conventional softwood cuttings or by division. There is no opportunity for variation in these circumstances. Take the classic Rosa ‘Iceberg’ this fragrant white climber or shrub rose will have little or no variation wherever you buy it in the world whereas the wild dog rose (Rosa rugosa) will have variable flowering, growth rate, leaf size and scent and that in a nutshell (or rose hip) is what we mean by natural variation.