When designing a planting scheme, make sure that you leave enough space between plants so that they have room to develop to their full size; if planted too close together, they will need to be thinned to avoid becoming overcrowded. However, there may be situations when close planting may be used to provide a particular design feature, such as a parterre or knot garden.

Plant spacings and distances can depend upon climatic conditions, the soil and the maturity period for the species or cultivar whilst the garden scheme is developing. Whilst young plants are cheaper than more mature specimens of the same species or cultivar, there may be a wait of several years before the planting begins to look mature. The decision on whether to plant a cheaper young specimen or a more mature plant that will offer instant impact will obviously depend on the budget available.

As a general rule, the use of fast-maturing plants and close planting creates a good short-term impact, but more maintenance, thinning and renewal will be needed in the longer term. A balance between fast- and slow-growing plants will give the most satisfactory results. Using temporary fillers such as colourful bulbs and annuals in the spaces will provide plenty of interest at the outset while the other plants are becoming well established.