South is home to 10% of the world’s plant species and 7% of its reptile, bird and mammal species. The National Red List assessments indicate 10% of South Africa’s birds and frogs, 20% of its mammals and 13% of its plants are threatened.
The Cape Floral Kingdom is home to 38% of South Africa’s plant species. This region is also the smallest and most threatened of the world’s six floral kingdoms, with more than 20% of its plant species now close to extinction. As habitats are lost to urban sprawl, agriculture, pesticide use and the invasion of alien species, gardens become more important as places to reconnect with nature by creating more diverse landscapes.
Biodiversity Gardening
The theme for International Day for Biological Diversity on May 22 is “Our Biodiversity, Our Food, Our Health”. In nature, there is a natural balance in the ecosystem, but in many home landscapes there is less variety and this is why the system often fails. Biodiversity gardening is multi-purpose gardening; it is about the interaction between humans and nature to the benefit of both.
A biodiversity garden provides a habitat for bees and birds, with rocks for lizards to hide. Picture: Lynne Yates
It is about creating an environmentally friendly and productive garden for the homeowner and a foraging habitat for wildlife. It is a garden where plants are chosen to suit local conditions, and invasive plants are removed to provide space for these desirable plants; where no insecticides or herbicides are used so the garden will be filled with birdsong and butterflies, bees and insects.
Benefits of outdoors
Today’s children are spending less time outdoors, with the result that many are disconnected from nature. Author Richard Louv, in his book Last Child in the Woods, coined the term nature-deficit disorder to describe childrens’ lack of outdoor activity and disconnection from nature.
A wall built from logs provides a home for insects and a pantry for birds. Picture: Jon Enoch/RHS
He says: “In nature, a child finds freedom, fantasy and privacy: a place distant from the adult world, a separate peace.” That is why biodiversity gardening is so important and beneficial to all people, especially to children. It is about spending time outdoors and connecting with nature.
Planting for pollinators
Pollinators are vital to biodiversity. Encourage pollinators to your garden by growing flowers that produce nectar and pollen, especially plants indigenous and local to your area. Single-petalled flowers are easier for bees to access, clusters of flowers easier to locate.
Butterflies need plants in all phases of their life cycle. Picture: Kay Montgomery
Butterflies need plants for each stage of their life cycle – egg, caterpillar, chrysalis and butterfly – and flowers that bloom in different seasons. Include plants of varying heights to attract large and small butterflies.
Rocks that hold water are favourite places where butterflies may drink and heat their wing muscles for flight. Shallow mud puddles are a source of water and minerals. Plants that provide nectar, berries, seeds and fruits through the seasons will bring the greatest variety of birds.
Plant mixed indigenous hedges and thickets of shrubs where birds can find protection and a place to build nests. Fallen leaves and dry twigs under shrubs and hedges are food larders for foraging thrushes and robins. In a sunny, open area in the garden establish a mini-grassland, where indigenous grasses play an important role in stabilising the soil and maintaining an ecosystem that provides a habitat for insects and shelter for small wildlife.
Log piles, mulches, rocks and low walls built of logs provide a pantry of insects for birds.
Single-petalled flowers are easier for bees to access. Picture: Lukas Otto
An edible mini-forest
An edible ecosystem can be introduced into an urban garden. Edible forest gardening has been practised in Africa, Asia and South America for many years.
A forest removes air pollutants, tree roots control water run-off and protect soil from wind and erosion, and fallen leaves enrich soil fertility. In the initial stages of planting this forest there will be lots of sunlight and space, but do not over plant or you will find that as the plants grow, there will not be sufficient light to reach the lower layers.
Ask your garden centre for advice on pre-planting preparation of the soil and suitable trees and shrubs to suit your conditions. Layered planting applies in an edible mini-forest garden as in natural forests. The top canopy of fruit and nut trees is planted to allow filtered sunlight to reach the lower layers.
Fruit and berry shrubs form the second layer, followed by vegetable and root crops, and finally herbs and edible ground covers. Vertical edible vines can also contribute to the food supply.