In refined and intensive plantings, nursery grown herbs are planted out. This is done in a global fashion, using a design as a guide only: one plants out spontaneously and intuitively by hand. The species are planted in such a way that the planting matches the plants’ natural growth patterns, that is to say, in large groups or swathes, in smaller units, a few together or as specimens. The patterns follow the images one has seen in the field or one’s own ideas. A knowledge of vegetation structure, a feeling for naturalistic composition and personal creativity produce limitless variation. Choice of species, combinations and composition decide the degree of refinement, all matching the variation of the woody plants present. One always plants out in a wide to very wide spatial arrangement, never using equidistant or regular rows or symmetrical arrangements. Thus, one allows room for spontaneous evolution and differentiation.
In this manner one can obtain vegetations with a strong impact, composed of species with an abundance of conspicuously coloured flowers (e. g. Anemone nemorosa, Corydalis solida and Corydalis bulbosa, Primula vulgaris (syn. P. acaulis) and Primula elatior), as well as species with an attractive habit and foliage, or species whose aesthetic appeal lies in their ability to melt into a ‘mass of green tapestries’ (such as Oxalis acetosella combined with Phyteuma nigrum, Arum maculatum and Blechnum spicant, or Chrysosplenium spp. with Primula elatior, Cardamine amara and Cardaminepratensisi).
Maintenance will range from very intensive for open vegetations with ‘refined’ species to less intensive for the more closed vegetations. Other species have their own place, from the lighter woodland fringes to the inner parts of the dark wood. The light – admitting crowns of a birch stand, supported by the fragile white trunks, combine extraordinarily well with the vivid tapestry of Chelidonium majus underneath. Where shade reigns during the summer, a white cover of Asperula odorata is perfected by the tender spring green of Athyrium filix-femina.
Along a forest path, single masses of Aconitum lycoctonum present to the visitor their pale yellow, fine flowers, with an astonishing natural generosity. Under the wood, where in spring plenty of growing opportunities exist for herbaceous plants, showing a massive bloom of Pulmonaria, Primula or Viola reichenbachiana, in summer the atmosphere is subdued and sober. Its strength now lies in species with strong foliage shapes, shades of green and variation in habit. Combinations with ferns are excellently suited to achieve this: Blechnum, Dryopteris spp. with Convallaria majalis, Sanicula europaea, Maianthemum bifolium or Lamium maculatum. Spots with dappled shade are the situations par excellence where filtered light, varied shades of colour and green, foliage shapes and habit contours can play a subtle game.
Woodland and water edges and fringes all offer their own opportunities for perennials. A wide variety of habitat elements that one can use meet at those points: light and shadow, moist and dry, cool and warm. They are the situations where lateral and back lighting are found in continuously changing strength and effect. Petasites hybridus, with its powerful habit, is very suitable for large-scale situations, it combines a spring flowering aspect with a long summer effect of great ornamental value. Doronicum willdenowii or D. plantagineum, on the other hand, are very colourful for a short period during spring, vanishing completely in summer, and, in doing so, giving space to other species such as Campanula.
The maintenance and management of refined, aesthetic vegetations such as these consists of weeding out spontaneously appearing, unwanted species, but, more importantly, of closely and carefully monitoring its evolution into more or less desirable forms. From this, the way to go ahead arises as by itself: leaving it alone or intervening and, in the latter case, how, when and into which direction, all depending on what one considers as desirable. The weather circumstances through the seasons and the years greatly influence these decisions, especially the quantity of rainfall and the occurrence of frost periods. Wet years, for instance, especially when a few of them occur in a row, show a dramatic increase of many species, not just through the strong growth of spontaneously germinated young plants, but also by the increased vegetative growth of existing plants as a result of greatly reduced moisture competition with woody plants. Arum maculatum, Lamium galeobdolon, Viola spp. and Stellaria nemorum are good examples. Conversely, dry years may have a positive influence upon the development of relatively drought-tolerant species. Within plantings, the compositions may now be dominated by one species, then by another, fluctuating between retraction and recovery. In this manner, Anemone nemorosa may dominate over Maianthemum bifolium in wet periods, whereas the latter will take over during very dry summers.