Retaining wall at a vineyard in Meißen/Saxony, shoot trellis fan forms are popular because they symbolize the growth of the plant striving for progress. On windowless and other slightly structured surfaces they can be - individually or in group - an enrichment. In edge areas etc. they can be constructed asymmetrically (see 6060). On highly articulated facades (with windows, cornices, etc.) fan systems are often disturbing. Here most common orders are only for vertical and horizontal lines. They are preferable because they 'absorb the existing structures' and 'continue' in design. A diagonal form language is then up to the plants and their instincts, which so naturally complement the grid system of grow and 'blur' together. Fan shapes are ideal for many plants, other than lurching ones like Wisteria. Please consult climbing plant and planning aids.