In the wild, in our climate, wherever there is sufficient light, bare soil quickly disappears. Within a few years, alder trees, blackberries and salmon berries take over from grass and wildflowers. Natural landscaping mimics ecosystems, resulting in sustainable, low-maintenance ornamental or productive gardens, using plants of our own choice. The ideas can be applied to forest edges, orchards, meadows and perennial borders, avoiding monoculture and bare earth.
There are six layers of plant growth to consider: a canopy layer of mature trees; under-storey trees; shrubs; herbaceous plants; ground covers; vines and climbers. The Wikipedia definition of forest gardening is “a low maintenance sustainable plant-based food production and agroforestry system based on woodland ecosystems, incorporating fruit and nut trees, shrubs, herbs, vines and perennial vegetables which have yields directly useful to humans,” using all of these layers.
A key component of this system for a productive garden is the choice of plants. The mature trees may be already in place, dwarf fruit and nut trees grow beneath them. Raspberries, huckleberries and currants fit in the shrub layer. Many vegetables, such as carrots, need too much sun, but several herbs, rhubarb and leafy vegetables (dandelions?) thrive. For example, comfrey is grown to use as a natural fertilizer or applied as a mulch. Many hedgerow flowers attract beneficial insects. Ground covers include strawberries, mint and clover.
In an ornamental garden, the range of plants for each layer is enormous, but the herbaceous layers are often empty, leaving space for weeds. Self-sowers such as foxgloves, columbines, forget-me-nots and the native fringecups or tellima provide cover in winter and can be edited out as more valued perennials fill out in late spring.
Even in a traditional vegetable garden, bare earth can be avoided by sowing a winter cover crop after harvest. This reduces the loss of nutrients during heavy rains and also blocks weeds. Turning a lawn into a meadow with long grass, spring bulbs and perennial flowers such as ox-eye daisies and yarrow avoids a monoculture, and regular mowing and watering are not necessary.
A certain amount of work is necessary to cut the meadow, remove the forget-me-nots and turn in the cover crops each year, and the prospect of a garden of wild flowers does not appeal to everyone. Some plants are invasive, and should not be encouraged. But on the whole, the benefits of a natural garden outweigh the disadvantages.
— Sheila Watkins, Master Gardener