There are a few common mistakes people make when drawing up their own landscape plans. These mistakes are not usually made by landscape contractors, who are trained to avoid them.

The first group of mistakes relates to the idea of scale. We have all seen the conifer that has “taken over” a plot of land and now towers over the house, dropping the occasional branch in a high wind, shedding needles onto the roof and, although beautiful, being a general nuisance. Bought as a tiny tree, it was planted in the wrong place – too close to the house – and its owners are living to regret it. Similarly, shrubs are frequently planted too close together, because the planting plan did not take into account the size to which each would grow, or, worse, there never were any landscaping planting plans. It is important to clearly identify the species of trees and shrubs you intend to grow on your site, and then to establish how tall and how wide they will eventually grow. Often that information is provided on the label when you purchase the item, or you can look up the details in an appropriate gardening book, or online. Once you know its final size, leave sufficient space for the plant to grow to that size without intruding on other plants, or structures, in the garden.

Scale should also be taken into account when you are planning paths, steps, terraces and the like. Frequently, these areas are made too small to be comfortable – possibly because their designer is locked into thinking in indoor terms and does not appreciate that being outside, with the sky for a roof, needs a large canvas and a broader brush. The “walls” of an outdoor room are much further apart than those indoors, so in your landscaping planning ideas you need to think “wide” for paths, “generous” for steps and “comfortable” for terraces. Two people should be able to walk easily alongside each other on paths and steps and there should be ample sitting space on a terrace. Remember that terraces usually hold outdoor furniture, containers, barbecues and so on, all bulky items that take up space.

The second group of mistakes relates to perspective – how things appear as they recede into the distance. Because a landscape plan is, necessarily, made on paper, and is therefore two dimensional, it is very hard to imagine the third dimension and to get an idea of how it will all look from eye-level. Again, your landscaping contractor, who is educated in design techniques, will be able to do this for you.

If you have a small garden and want it to look larger, a useful trick (one that was often used by Renaissance landscape designers) is to have a tapering path leading to a focal point, such as a statue or an arbor. The path starts out wide and narrows as it goes towards the feature. However, you need to remember that, when looking back down the path, the opposite, foreshortening effect will be brought about. This may not matter, but is worth considering.

If you are planning a curving path, or any other freeform feature, perhaps a pond, remember that in two dimensions curves may appear quite gentle, but once the plan becomes reality the same curves may seem excessive. It is best to check curves by marking them out using twine, or even your flexible garden hose, in the place where they are required, in order to create a smooth-flowing design that looks satisfactory from every angle.

The old “KISS” (Keep It Simple, Silly) idea can apply to your landscaping plans as it does to other aspects of life. By planting too few items rather than too many; making sure plants are at a suitable distance from the house or other structures; allowing paths and steps generous proportions; and not exaggerating freeform features, you will be rewarded with the “elegant simplicity” that is the hallmark of good design.