While looking for material for landscape design of properties, it has become apparent that material of whatever size is in short supply.

Having said that I should perhaps justify what I believe is part of the reason ? excluding Fabian ? many gardens are overplanted or simply as I have noticed on many properties, plants are too close to each other within their designated area.

This is not only a waste of money in the purchase of plants but also labour for unnecessary time consumption and of greater concern, future maintenance and perhaps removal of overcrowded plantings.

Whether we are looking at buying one plant, redesigning a small area or carrying out a full design, certain criteria need to be considered. These can be described as plant use, functionality and placement.

Why do we select a certain plant and what is its use in the landscape? If it is for purely aesthetic reasons, ask the questions, when does it flower, how high will it grow, does it like sun or shade, is it wind and salt tolerant? By having such information you are more than likely better informed as to your choice and range of material.

If you are looking for a plant to grow under your window regardless of whether the window may or may not have a shutter, it is pointless buying a flowering plant that will grower higher than the lower part of the window if it is constantly cut back.

Once a plant outgrows its perceived limits it is (hacked) pruned hard back often before it has even had a chance to flower!

The answer of course is to know the ?mature? height of the plant prior to planting.

Plant use covers many aspects from a design viewpoint, it may be to hide a not to attractive area or item, it may be a plant to make a bold statement from a particular room or area or simply in a combination of other selected material.

Selection for the best result will make or break the ?personality? of the plant; a large plant in a small area will look out of place, whilst a small plant in a large area will be lost. When designing a shrub border, understanding growth rates is important, as one does not want a particular plant to outgrow its neighbour to its detriment.

It is also important to mix plants which overlap in their interest and flowering time, in other words if one plant is looking ?off? then its neighbour should be in full bloom or have a strong characteristic to offset the down side of its neighbour.

Functionality encompasses use in a wide range of needs, including screening, security, separation, directional and ?warning? sign and entrance/exit feature.

Planting an evergreen hedge creates screening; if the hedge is not evergreen it defeats the objective required in the first place, i.e. creating privacy.

Many plants have thorns or other nasty appendages which when used in certain locations deter access to the designated zone, thus reducing entry.

This is a basic form of security, but few people would ever wish to tangle with a mature Kei apple (Dovyalis caffra) or Natal plum (Carissa macrocarpa).

Separation, unlike screening, does not totally hide the area in question, but simply for whatever reason demarcates two areas.

In such areas the selection of plant material will vary contingent on the need, e.g. English Box (Buxus sempervirens) can be used around an herb garden or to show a change in level, whereas Ligustrum sp. (privet) could be used to separate a rose garden from a mixed shrub border.

The use of directional and ?warning? plantings is part functional plantings and part design and layout, this might appear a strange approach to such ?signage?, but it is realistic when done properly.

Directional plantings are purely and simply creating a design when the planting leads one to a specific area, whilst warning plantings are similar in selection to security plantings. Hedges or screen plantings block access to areas and therefore direct one to the nearest opening be it a footpath or ?gap? in a hedge.

A mass planting of Agave (century plant) is a deterrent to anyone walking through the planting as a short cut, so planting this type of plant against a rock cut or other no go area, acts as a visual warning.

In any design plant knowledge and growth association are paramount in the success of the layout. Plants that have the potential to grow large should not be placed in small or confined area, as they could well be a problem in the future, and often a costly exercise.

Plants must co-exist with their neighbours; therefore the planting space between each plant should be enough to allow ?free? growth between competing plantings. This is also the case when planting near a road or path. I recently saw a new flower bed design with a footpath running through it, and immediately adjacent to the path was a Phoenix canariensis (Canary Island Date) with a leaf overhanging the path!

Plants grow and their potential height and width is important if your choice of material is to grow without impediment and not create a problem to its surrounds. Planting a hedge or indeed any plant too close to a road, boundary wall or path will inevitably lead to the need for constant pruning of growth with the result being a reduced flowering habit, and hence one asks, ?where have all the flowers gone?.