Creating a biodiverse eco garden

Biodiverse eco garden infographic.

The principles of a biodiverse eco garden

Creating an eco garden is all about bringing local biodiversity into your garden landscape. If you want a dynamic eco garden, you should try to mimic the patterns in nature and the services plants provide to wildlife. The above infographic describes a biodiverse eco garden and the principles involved, which are unpacked here.

Plant locally indigenous plants

Local plants are well adapted to the soils and climate of your area and therefore hardier and need less care and less water. You will be surprised at the number and beauty of all the indigenous plants available at nurseries today. Before planting, remember to prepare the soil well to give them a great start. Mixing in some organic compost and topsoil is useful for most soil types. Add some coarse sand to clay soils for better drainage.  A variety of indigenous trees, shrubs, bulbs and grasses will provide nectar, fruit, seeds, bees, caterpillars and butterflies for birds. There are many books available about how to attract birds to your garden. I recommend the recent Garden Birds in Southern Africa by Duncan Butchart.

No lawn or a small patch only

A manicured lawn is pretty but in reality a very thirsty, green desert. It provides little besides a soft space to walk/play on, a spot for your dog, and sometimes a few worms for a few bird species. A natural grassland on the other hand provides much more value and uses far less water. It’s exciting to explore along stepping stones running through a wild grassland or eco garden. The garden keeps changing through the seasons and as it evolves into a mature garden. If a patch of lawn is essential, rather plant an indigenous lawn grass that uses less water and can occasionally be left to seed which provides more food for insects and birds.

Create a wetland

A wetland is a very rewarding garden feature. It adds more biodiversity and beauty to a garden and water for birds to drink and bathe in.  Even a small one in a large shallow basin with some water plants and fish is useful. A wetland should always have a shallow, sloping edge for easy access by birds. A little flowing stream with stones and pebbles is a favourite spot for bathing. The minimum is a birdbath or small fountain placed near shrubbery or under a tree where the birds feel safe to bath. It should be about 1 m above the ground for a faster escape from a cat or other predator.  

Leave the leaves and mulch

Leaving leaves lying in the garden or adding a 5 cm deep layer of mulch such as nutshells, bark chips or pebbles will reduce water loss from the soil by up to 70%.  It also reduces the growth of weeds as many seeds don’t reach the soil and seedlings battle to grow through the mulch. The leaves or mulch will slowly decompose and add nutrients and minerals to the soil and feed the soil microbiota. Healthy soil, healthy plants!

Group the thirstier plants together  

Some plants like Clivias and forest lilies need more water than others. Plant these species together in the same area so they receive the required amount of water and less thirsty plants don’t get overwatered.     

Watering, drip irrigation and harvesting water

To ensure that watering is efficient and most of it not lost through evaporation, a drip irrigation system is the best. Water is provided directly to the plant base at the soil level. Install rainwater tanks to harvest rainwater from roofs and connect them to the drip irrigation system, or use the rainwater to top up the wetland/water features. During summer rather water at night instead of during the heat of the day. This will save water as less water will be lost through evaporation.    

Remove alien invasive plants

Invasive alien species are a no-no as they cause much harm when they spread into surrounding areas beyond your garden. It is also illegal to have a listed invasive alien plant on your property without a permit. Before removing them, check whether any of the invasive trees are being used as nesting and roosting sites by raptors and do not remove those; rather remove the saplings that grow and prevent their spread outside your garden. Birds bring in seeds of alien plants they’ve eaten and deposit them in their droppings in your garden, so keep a lookout for young invasive plants and remove them quickly. A useful list of invasive plants can be found here.  

Build a bug hotel 

This can be a woodpile, tree stumps in the garden, anything of your own design to provide a shelter and breeding place for insects, geckos, and other small creatures. The more wildlife in your garden the better for birds that feed on insects and live food. Mice, spiders, and ants are some of the creatures that play an important role in maintaining an eco garden and need places to shelter.  

Provide nests or materials

A sisal log is a quick and easy nesting solution for a variety of cavity-nesting birds such as barbets. Owl boxes and other smaller nesting boxes are also available. Bits of straw or natural fibres, grasses, and sedges will be useful for building nests. A dense thicket of shrubs provides a place for the shyer birds to breed. A dead tree left standing will be used by birds and other creatures.    

Feeding birds

Supplementary bird food, such as seed, suet, mealworms, fruit, and sugar water, does not provide all the vital proteins birds need and they must source food in nature too. Artificially feeding birds will attract them to your garden, especially when your garden is not yet providing natural foods for them if it is a new eco garden or not diverse. Once your eco garden has grown it will provide most of their vital food requirements, but you can supplement with bird food occasionally and in winter when food is scarcer.  

No pesticides, herbicides and poisons

Despite many products claiming to be environmentally friendly, they all kill a specific type of bug or many different kinds. Birds that eat the poisoned creatures die too. Often their health and breeding success may be affected if they are exposed to poisons in their environment. Rather let the birds, geckos, spiders, and insects control the bugs you consider to be pests in your garden. A natural balance will be established and most plants do recover from periodic infestations. Even if some plants are lost they can be replaced. 

For ideas and examples of bird-friendly eco gardens, click here.