How do I know how big my plants are going to grow?!

Wherever your garden is, and whatever kind of garden design or landscape gardening dilemmas you are trying to solve, there are similar themes that always seem to come up. As a garden designer in Glasgow, this is no different, and judging appropriately-sized plants is one of these garden design factors that comes up. Garden designers and landscape gardeners in Glasgow and anywhere else you go will have this at the forefront of their minds when creating their planting plans.

Can you think of a plant in your garden that is taking up too much space? Or perhaps you’ve bought a new plant that has been swamped by its neighbouring plants? This is a critical factor in plant selection for garden designers, and it ties in closely with the garden design rules of balance and proportion within your garden. Plant labels will always show the ultimate height and spread of the specimen that you have just  purchased, and more detailed labels will tell you how long it will take the plant to reach this size.

You can also find information easily online anywhere that offers garden advice or garden design ideas.  The consideration of plant size is especially important when planting trees, specifically with trees that are going to grow too large - something I have encountered many times in gardens in Glasgow. Trees are often planted too close to houses, or simply in a position where their ultimate size will look disproportionate. Tree roots cause problems too, and it should be borne in mind that a roots extend to at least the same extent as the outer line of the crown of the tree. For shrubs this consideration of spread/size is predominantly an aesthetic one, as well as being a way to ensure the happiness of a plant.

How ideal an environment is for a plant is something to remember too. Often plants in Glasgow may not reach their full size potential but will still be happy. Shrubs should be positioned in a place where their ultimate size will be in keeping with the size of the bed and the (ultimate) size of the plants already there. In reality this may mean that you initially have gaps in your flowerbeds that  become overgrown with weeds. The technique here, if you know you’ll be able to keep on top of  managing your plants like this, is to plant more tightly and thin out or transplant plants as everything matures.

For gardens at flower shows, plants are planted very densely in order to create instant impact and give the appearance of a mature garden, but to do this in a real garden requires careful trimming and pruning to keep plants from fighting with each other. Remember too that competing plants are under a bit of stress and so are more likely to pick up pests and diseases. In my garden, I keep fairly densely-planted flowerbeds and trim/prune as required, whilst feeding well to keep them strong and lush. This management of shrubs to keep them to a sensible size is not a recommended technique with very large shrubs and trees. The reasoning being that it’s likely someone else will own your garden one day, and in time the plant will grow to an unmanageable size.

Tom works as a garden consultant and adviser and is based in Glasgow. He is a Chartered Horticulturist, landscape gardener and award-winning garden designer with experience in horticulture everywhere from France to Somerset to Aberdeenshire. Services offered include everything from advising on Japanese Knotweed removal in Glasgow, to creating planting plans for clients in London.