The principles of good design by being universal rules, apply in any and every situation where different objects are put together to make an aesthetic impression.
This is the case whether one is writing a novel, composing a symphony, choosing an outfit for a social event, or creating an ornamental garden.
Design principles are commonly and mistakenly confused with personal taste or style.
Personal taste, legitimate as it may be, is subjective.
Good or bad do not come into it.
On the other hand, mistakes or achievements in design occur when the rules are either disobeyed or adhered to.
Design principles are therefore objective.
There are six main elements of design - unity, diversity, simplicity, balance, scale and emphasis.
This article focuses on the last of these elements - emphasis.
Think of a person who talks in a monotone or a piece of music where the tempo never changes.
These are two cases where emphasis is lacking.
Emphasis has to be present in a garden for exactly the same reason and it can take various forms.
It can be powerful, such as in the case of a strong contrast, or gentle and subtle, such as where a group of low growing grasses emerges from a mass of prostrate ground covers.
Indeed it's important to distinguish between the different anatomical and morphological features of different species, because emphasis is achieved by a plant whose color, size, form, shape or leaf texture contrasts with the other plants.
In order to succeed in the use of emphasis plants, a couple of points should be borne in mind.
*An emphasis plant can differ in some of its characteristics such as size and shape from the rest of the plants in the group, but not in all of them.
So if the contrasting plant has exceptional foliage color for instance, it should be similar to the main body of the plants in such attributes as size, form or leaf texture.
In fact the less attributes in which the emphasis plant is different, the stronger the contrast is likely to be.
*Emphasis plants should be used as sparingly as possible.
Actually, any of the elements of design only work when applied in conjunction with the other elements.
A contrast is achieved on condition that there is a unified mass against which to make a contrast in the first place! While color contrast, whether created by flowers, fruit or foliage, is an obvious factor determining the emphasis potential of a particular plant, I'll give a few examples of plants whose shape and form make them ideal candidates for this role.
The list is limited to species suitable for dry, Mediterranean climates.
Plumeria rubra: A beautiful sculptural plant from tropical America.
In tropical climates it grows into a medium sized tree, but the summer dryness and relative chill of a Mediterranean winter stunts its growth to 3 or 4 meters.
While it should be primarily grown for its form and shape, the Plumeria also has attractive and fragrant flowers.
It is unsuited to areas where the winter temperatures drop below -2 or-3 c.
Yucca sp: The classic sculptural plant for a dry climate garden.
The problem is its spiky leaves that can be very dangerous, and therefore it should be planted well away from paths and entrances.
Nandina domestica: is an evergreen shrub from Japan and China.
Sometimes known as Heavenly bamboo for its delicate texture and upright form, it makes for a gentle contrast with small foliage bushes like Pittosporum "Wheelers Dwarf" and Coprosma repens.
In cold winter areas, the foliage turns reddish brown.
While its white flowers are not particularly showy, the red berries that follow in the autumn are highly ornamental.
Ornamental Grasses: This term includes real grasses, that is plants belonging to the family Poaceae, (Graminae) and plants from other botanical families that have a grass like habit.
Examples of the latter include Phormium tenax (sensitive to over-watering) Dietes bi-color and various varieties of Liriope and Ophiopogon.
It is the feathery growth habit, and sword-like leaves that make grass like plants excellent material for contrast and emphasis.