You have a brand new site – a blank canvas – and it's decision-making time. What will you plant? Of all the landscape changes you can make, adding plants is possibly the most important. When you are at the choosing stage, there are three major considerations: the sort of site you are planting, what function the plants will perform, and the conditions your plants will encounter on the site.

The sort of site you have – its "character"– is determined by its position and its size. Is it a large acreage in the country, a tiny spot in the city, or something between in the suburbs? Large plantings, especially trees, which look magnificent in a country setting, may be out of place or a downright nuisance in an urban setting. Plants that thrive in mountainous regions may not do so well at sea level (although they can be grown there if suitable conditions are provided) and so on.

It is important also to look at surrounding plantings when deciding what to grow. If you chose your site because you enjoy the neighborhood, then it is wise to see what the neighborhood contains and keep your plantings in tune with others'. Or perhaps you are trying to blot out your surroundings? In that case, a different landscape plan will be necessary.

What sort of site do you have to work with? Has it been denuded of topsoil by bulldozers, so you have to start from the very beginning, building up a suitable substrate for growth? Or have you inherited some desirable natural features like rocks, trees, even a pond? In the latter case you may need to decide whether you will concentrate on plants that are native to your area, to make best use of the garden conditions to which the plants are adapted.

Buildings also play an important part in your decision-making. The sort of home you have influences the shape of your plantings. An obvious example is choosing tall stately trees such as poplars for an upright, formal home; low spreading shade such as a weeping elm for a sprawling ranch-type house. You may need to disguise ugly outbuildings – or to draw attention to an architectural gem by a sympathetic choice of plants.

What major functions do you want your plants to perform? Perhaps you need to plant a row of evergreens as a shelter from wind. If you want summer shade but winter sun, deciduous trees will be a good choice. Perhaps you want to soften the harsh outlines of a building with suitable plants, or provide a shady area for children to play.

Finally, the conditions the plants will encounter must be considered. Hot and dry? Cool and shaded for much of the day? Look at existing conditions of climate and soil and eliminate plants that are not suited to them. While much can be done to change conditions, often it is wiser to work with existing conditions and choose only those plants that need little or no maintenance to thrive.