In nature plants can be found growing on vertical surfaces like cliff faces or tree trunks. Understanding this growing environment is key for having log term lush and healthy plants on a vertical garden.
Typically a true vertical growing location is normally soilless and well drained, yet offers a stable support for roots to attach to. VGD’s cultivation technique replicates these conditions creating an ideal vertical growing environment.
Outdoor vertical gardens require a plant selection suitable to the local climate and sun exposure. For example a sun-exposed wall in the Mediterranean can be planted with aromatic plants like Lavandula, Thymus, Rosmarinus or Salvia, whereas a shaded wall in the same location can look almost tropical with plants as Arum, Davallia, Asplenium, Begonia and Fuchsia. As with any garden it’s key choosing the right plant for the right location.
Indoor climate normally equals low light levels and around 20° C. Plants for such environments can be found under the tropical forest canopy where little light filters through and life is adapted to deep shade. Common plants used indoors are aroids like Philodendron, Anthurium and Epipremnum, gesneriads like Aeschynanthus, Columneaand Streptocarpus, ferns such as Nephrolepis, Pteris and Cyrtomium.
Plants growing on other plants are called epiphytes and are a reliable group of plants for vertical gardens. They are more common in tropical climates as their roots are not in contact with soil, relying on frequent rain showers for water. Pictured is a bromeliad in the cloud forest along the Peruvian Andes.
Plants that grow on rocks are called lithophytes and adapt well to vertical gardens as they have roots that can hold them attached to a bare surface. As with epiphytes they require a growing location with good drainage. Pictured is a Xerophyta longicaulis in Drakensberg, South Africa.
Availability of water is a limiting factor for plant growth on vertical rock faces. That is not the case nearby waterfalls that often host a diversity of plants and can be an interesting place to study for the vertical gardener. The image above shows a waterfall in Madeira with the large growing fern Woodwardia radicans along both sides.
Aroids are a very useful plant family for the vertical gardener. There is an abundance of aroids with large and ornamental foliage that make spectacular accent plants, as well as inconspicuous varieties providing a reliable green coverage. Pictured is a Philondendron verrucosum in Costa Rica.
Begonias grow in the tropics and subtropics all around the world and is one of the largest genera among flowering plants. Many are found growing in shadowed locations below a canopy or on moist, shadowed cliffs. Such species are well suited for indoor vertical gardens, or on shadowed exterior walls where light intensity is low. The low light preference also makes begonias a common house plant of which there are innumerable horticultural varieties. Pictured is a Begonia multinerva in Costa Rica.
Ferns grow in a large variety of habitats, and many are well suited for vertical gardens. Pictured is a Davallia canariensis in Sintra, Portugal, one of few epiphytes in this region.
Vertical growing locations in nature often are soilless, such as cliff faces and tree trunks; soil simply tend to erode or fall off from such exposed locations. Plants here have roots that grow attached to the bare surface and fix them securely through storms and rain showers. The pictured pinnacles are in Wulingyuan, China.