Plant Solutions. Nigel Colborn

      With water becoming a scarce commodity and, in some areas, an expensive one, much attention is being turned to low-water planting schemes. Typical natural landscapes, whose arid beauty is well worth imitating, occur in such places as the rocky Mediterranean coastal regions, the southern tip of Africa, the American Chaparral and in many parts of Australasia. Such areas have amazingly rich floras and many of their native plants have become garden staples. Gladiolus, Lavandula and Eschscholzia are examples of the thousands of widespread plants which enjoy similar conditions.

      Trees, in such habitats, tend to be small and slow growing and many of the shrubs are evergreen, often thorny, either with waxy cuticles to their foliage, or with silvery or grey leaf surfaces. The secret, with Mediterranean gardens, is to include a rich number of short, medium and long term feature plants. Winter and spring bulbs, which grow during the cool, wet periods, give short spells of drama, but disappear for much of the year. Speedy annuals, such as Cerinthe or Papaver will splash summer colour among the shrubs which will become increasingly gnarled and characterful as they age, providing a longer term outline. Mediterranean-style herbs come in and out of colour all year, linking seasons and extending colour, from such spring bloomers as Erysimum to the autumn flowering, vivid orange Zauschnerias.

      Cottage

      The romanticised concept of a cottage garden conjures up images of roses or honeysuckle round doorways and window frames, mossed apple trees, flower borders with plants all hugger-mugger, a vegetable patch and possibly even a chicken coop. To be well planted, however, a cottage garden must retain elements of order and pleasing form. Colours should be blended with care, especially where cultivated varieties of plants with large flowers are used. Plants look best when arranged to complement one another, with consideration given to height, spread, denseness or looseness and so on. They must also be chosen for succession so that an autumn cottage border is as attractive as an early summer one.

      Naturalistic

      The aim is to mimic plant distributions as they might occur in nature. Apparently random groups of plants are arranged in drifts or small groups of irregular sizes and shapes. Where shrubs or walls obstruct light, shade plants are placed just as they might grow naturally, in a wild setting. Plants can be allowed to seed around, even if this means that they spill over onto pathways, softening lines and edges and extending their colonies.

      Closest to a truly wild, flowery meadow, this is a style which contrasts sharply with contemporary landscaping where hard materials and objects such as gabions or sheet metal are used. Grasses blend sweetly with other perennials whose gentle outlines are full of movement and dreamy romantic colours. Woodland plantings are also best when kept as naturalistic as possible, and where woodland species can be allowed to propagate themselves, and perhaps blend with native species in the same habitat.

      Formal

      Bedding, a traditional planting style, is still popular and, despite going through minor fashion changes, remains one of the great Victorian legacies. The importance is to understand that plants are used as colouring materials to paint surfaces and make patterns or shapes which, for the most part, last but a season. Overwintered bedding which reaches its climax in mid-spring – perhaps six months after planting – is a dying culture but has immense value.

      Meadow and cornfield

      Growing plants naturalised in grass is a technique that still has some way to go before all its secrets have been revealed. As a growing medium for spring bulbs and early flowers, grass has long been proven, but as a feature for a summer garden, particularly on a small scale, there is still some way to go. The decision has to be made, each season, when to cut the meadow back and how to manage the aftermath in late summer and autumn.

      A stimulating composition in which colours and textures work well together. The velvet leaves of the verbascum find some sympathy with the fluffiness of the Ageratum flowers, but when their tall yellow flower spikes emerge, later in the year, the effect might be a little too startling!

      Annuals such as poppies and cornflowers are frequently, mistakenly, planted in grass meadows where they are bound to be shortlived. However, a new concept in gardening is the notion of a small fragment of cornfield, even sown with barley or wheat, and where such annuals could be made to thrive. Management is simple: ‘harvest’ in late summer, removing straw and plant material after it has shed its seed; disturb the ground and wait for next year’s self sown crop to grow!

      Paving and gravel

      Even the most unsympathetic hard landscaping can often be persuaded to yield up a planting opportunity or two. Where space is limited and plants few, immense care is needed to select exactly the right ones, since each specimen will be making a large statement. This is like comparing a string trio, where a missed note on the violin jars the whole performance, with a huge orchestra and choir where, if a bass sings temporarily out of tune, only the sharpest ear will pick up the drone. Not only must the most suitable plants be selected, for such key roles, they must also stay in near perfect condition.

      Borrowed landscape. The pastoral scene, behind the garden wall, makes a charming backdrop for more dramatic plant grouping in the foreground border.

      Problem Site

      Every planting site comes with its own special advantages and its own problems. It is important to assess both, in terms of plant choice. Disadvantages should not be viewed in negative terms, but should be recognised so that plant choice is limited to those species which will thrive in the prevailing conditions.

      The main challenges to plants are caused by the following typical situations, either in isolation or – more usually – in combination:

      Exposure to wind Plant robust trees and shrubs to windward, to create shelter. Hedges and shrub screens are more effective at wind protection than walls or solid fences which cause damaging eddy currents. Be prepared to plant for more extreme conditions, as your sheltering plants develop, and, as shelter becomes more available in the garden, adjust your planting plans to take advantage of the new conditions.

      Excess shade Thinning out the overhead branches of mature trees often lets in more daylight. It may also help to paint any surfaces with white or a light colour. In moist shade, select plants from damp woodland habitats. Where trees are intended, as part of a planting scheme, select varieties such as Robinia, whose leaves are late emerging. The delay will enable spring plants under the branches to flower and begin to seed before light levels are reduced.

      Excessively dry shade Moisture-retaining mulches will help, as will establishing a dense vegetative ground cover. Under trees, focus on plants that flower during winter and spring, when overhead branches are bare. Be content with a narrow choice of plants, but try any that you think might survive. All conditions differ, and plants that languish in one person’s dry shade, may perform well in another. Once you know the plants that will live, focus hard on these, selecting them in as many different forms as you can.

      Excessively hot, sunny and dry Hardly a problem site! The number of plants that love such hot conditions is vast and varied, from desert succulents to winter and spring flowering bulbs. Count your blessings and get to love small bulbs, sedums, helianthemums, dwarf irises and so on.

      Excessive wet – especially when caused by poor drainage Good drainage is essential for most plants to thrive. However, some wetland species are better at coping with poor drainage than others. Try to minimise the problems associated with bad drainage by installing raised beds, or following the advice given for excessively heavy soil below. Select wetland plants such as hostas, water iris, ligularias and Lobelia cardinalis.

      Heavy or light soil Surprisingly, the same improving measures apply to both: dig in as much compost or leafmould as possible, building up the levels of organic matter. Heavy clays can be improved by digging in coarse grit, leaf mould or rotted compost. Light sand also benefits from a boost