Materials and construction Material properties and material qualit y
A distinction is made between three different root systems: tap, fibrous or horizontal root systems. Deciduous trees and shrubs are seldom used indoors; broad-leafed evergreens, conifers, shrubs, and palms predominate. They create their effect mainly by their habit, leaf shape and colour. Some species can be grown as hedges or for topiary work. Climbers and creepers are also counted as broad-leafed plants. They cannot stand independently, and need strong tendril support such as walls, trellises or wires to grow upwards. Herbaceous perennials often form clumps or tufts, like most grasses, or grow via runners. The vitality of the above-ground parts dwindles in some species, or they withdraw completely; then new buds form close to or below ground level. Many evergreen perennials with ornamental foliage from tropical or subtropical climates that flourish in shadier locations are suitable for indoor planting, as underplanting for solitaire shrubs and trees, for example. They make an impact through the colour, shape and texture of their leaves, which are often variegated or have white e dges. Flowering perennials enhance an indoor setting with the colour, shape and fragrance of the blossoms they develop in good locations. Whether the impact made by perennial planting looks natural, structural or abstract depends on the nature of the planting scheme as well. Mixed perennials, especially using plants from the same area of origin, look casual and natural. Drift or block plantings emanate a sense of calm and can provide harmonious underplanting to set off woody plants. Ferns, which usually have feathery fronds and usually come from shady woodland locations, are well suited to many interiors. They can survive with less light, but need higher humidity levels. Large tree ferns look very impressive as solitaires, while vari eties that serve as ground cover as dense underplanting or in vertical gardens convey an impression of luxuriance.
Many aquatic plants flourish indoors and make expanses of water look natural. They can be used as natural water filters, as in the Alterra ¶ p. 120 and Covent Garden ¶ p. 84 projects, or contribute to raising humidity by high evaporation levels or cooling by transpiration. Succulents come from arid tropical and subtropical areas. They can accumulate and store water in various plant organs in order to survive long periods of drought. A distinction is made between leaf, stem and root succulents, according to the storage location, but all combinations are also possible. The cactus sub-family originally came from arid areas of the Americas. Succulents and cacti make for easy-care displays in locations with extreme conditions, such as spaces that are sunny but difficult to access. Plant qualities Only high-quality, robust, healthy and vital plants from specialist suppliers should be used, to ensure that the indoor planting looks good from the outset. Pot and container goods are grown in such a way as to produce compact, dense root balls, like baled plants as well, and this means that large plants can be replanted. Only container goods can be considered for imports from other countries or transport over long distances. For perennial plants, the container volume is usually given in litres, to distinguish between the various ranges on offer. For woody plants, measurements are given in terms of height and width, as well as the trunk circumference for trees (measured at a height of one metre).
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