RHS Garden Planning Design principles In a successful design, the garden presents a pleasing, consistent whole that is in harmony with the house to which it is attached and with its surroundings. This can be achieved through considered choice of materials and plants and in the shapes and proportions that are found within the design. Unity Unity is the sense that the garden ‘adds up’, with no discordant elements. Unity can readily be achieved through the use of: • at most, no more than three different hard landscaping materials • repetition of a particular plant or plants (‘accent’ plants) • repetition of a particular colour, or restriction of the colour range • repetition of shapes and proportions Sometimes, however, sudden contrasts can add to the dramatic impact of a garden, for instance if a wild area is sited near (but hidden from) a more formal area. The golden section Found extensively in nature as well as in classical architecture, Renaissance painting and print advertising, this proportion is frequently used by designers to divide a space into two unequal but pleasing parts. To achieve this, divide a line in such as way that the relationship between the shorter of the two sections to the larger is the same as that between the larger section and the whole. The resulting proportion is an irrational number (like pi) whose precise value cannot be calculated. It approximates to 1:1.6. This proportion can be used extensively – for instance to determine the depth of a patio relative to its length; the dimensions of a pool (both formal and informal); the depth of a border relative to an adjacent wall or fence; the distance between uprights of a pergola relative to their height. The Fibonacci sequence Making the necessary calculations using 1:1.6 can result in some awkward values. It is sometimes simpler to use Fibonacci numbers instead, familiar to anyone prepared to admit to having read Dan Brown’s Da Vinci Code. The sequence runs 0 1 1 2 3 5 8 13 21 34, etc. each number being the sum of the preceding two. The way to use Fibonacci numbers in a design context is to isolate two adjacent numbers. The further down the sequence you go, the closer you get to the golden section – 21 x 1.6, for instance, is 33.6, not so far off the 35 you get using Fibonacci. The 5:8 ratio is often the simplest.
Symmetry and balance Symmetry and balance are not the same thing. Symmetry means the exact mirror image of something. It is obvious at a glance whether an object is symmetrical or not. Conversely, our perception of balance is more subjective. It is our understanding that two objects occupy a similar space or have a similar mass.
Symmetry is always very strong, but in practice difficult to engineer. Angles and measurements have to be exact. Symmetry usually implies extreme formality – as, for instance, in the garden at Versailles – and often involves the use of focal points. In an informal scheme, it is important to guard against ‘accidental’ symmetry, most easily avoided by using odd numbers (for instance of shrubs, conifers, containers, etc.)
Garden styles While design principles are universal, style is personal and often a matter of individual taste. Cottage garden style Implies majoring on flowering plants, planted informally (though the layout may be formal – box hedging is traditionally used). Roses, hardy perennials (geraniums, foxgloves, delphiniums, dianthus, poppies and peonies) and spring and summer bulbs are important. Annuals will extend the season in summer. Most of these plants are best in full sun. (Note, a cottage garden is relatively high maintenance, and is generally planned for spring and summer interest only.) A cottage garden often includes a kitchen garden. Oriental style Oriental gardens often contain few plants (and few flowers) and generally have a symbolic aspect. Rocks and raked gravel (symbolising rivers and mountains) are important. Plants include conifers, ferns, Japanese maples (Acer palmatum and A. japonicum) and hostas with some use of mosses. Glazed oriental containers work well. This style suits a shady site. Exotic/tropical style Suitable for a courtyard/city/roof garden or terrace. Large-leaved plants of borderline hardiness can be used to create a ‘jungle’ atmosphere – e.g. banana palms and loquats (Eriobotrya). In summer, shade-loving houseplants such as spider plants, tradescantias, ficus and orchids can be added. This style is useful where space is limited and plants have to be grown in containers. Minimalist style Here there would be a focus on hard landscaping and clean lines. Exact proportions are highly important – more so than the planting, which may be incidental. Clipped evergreens (e.g. box, holly, hornbeam, Portugal laurel) and ‘architectural’ plants with a firm outline (such as phormiums and Trachycarpus fortunei) would be appropriate.