A healthy and biodiverse garden will be one that is bursting with plants, humming with insect and bird activity and has rich, productive soil. Above all, it will provide a stimulating yet restful experience. Our gardens can be our personal way to improve the future for ourselves and the planet.
Favouring diversity and biomass has multiple benefits and a flow-on effect. For example, if wildflowers are encouraged in cracks in the concrete, rather than being sprayed or weeded out, beneficial insects will be nurtured. These in turn will pollinate food crops and prey on pest insects. Abundant plant growth ‘scrubs’ pollutants from the air and provides natural cooling in a time of global climate change. Here’s how to encourage a biodiverse garden at home.
Create healthy soil
Your garden should be managed so that plants and other organisms recycle organic matter. The goal is to preserve nutrients, encourage wildlife, reduce waste, and provide an optimum soil environment for plant growth. If all organic matter is returned to the soil, through composting or the ‘chop and drop’ method, the soil will become healthier, plants will thrive, and carbon will be absorbed from the atmosphere and stored long-term. Relying on natural organic matter for fertility also prevents nutrients being leached into the water table, as often occurs when artificial fertilisers are used.
Bring in the birds!
One of the great joys of having a garden is the presence of birds that come to visit. Native birds are especially welcome, and we can all do our bit to encourage the survival and proliferation of our unique and special range of birds. Domestic gardens can provide an important refuge for birds, particularly in winter when they often migrate to the relative warmth of cities to find food. Birds primarily visit our gardens for food — be it nectar, berries, insects or invertebrates such as earthworms. They also come to perch and to nest and (where possible) to enjoy surface water for drinking and bathing.
Trees please!
The most fundamental way of encouraging native birds into your garden is through plants. Taller shrubs and trees allow birds to feed in relative safety without having to move down to the ground, more frequented by cats. Some native plants are particularly attractive to birds. Tï köuka (cabbage tree, Cordyline australis) provides nectar for songbirds such as tüï, korimako (bellbird) and silvereye (tauhou) in spring. They then produce copious berries in autumn, appreciated by kererü. Another popular native plant which provides nectar in spring is köwhai (Sophora species). Some exotic trees are also favoured by tüï and korimako; they include Eucalyptus and coastal banksia, but these also become large trees. Nectar producing bottlebrushes (Melaleuca/ Callistemon species) are generally smaller-growing, but still grow into a small tree over time. Some Eucalyptus and other exotic species flower during winter, providing sustenance for birds at a time of year when few natives are in flower.
And some shrubs…
Various lower-growing native shrubs (which can be more suitable for smaller sections) also attract birds. Some are attractive for their berries in autumn; these include Corokia species and some forms of Coprosma. As Coprosma shrubs have separate male and female plants, you need to be sure that you plant female fruit-bearing ones. Other lower-growing plants, with flowers held relatively high above the ground, attract nectar feeding birds. These include harakeke (New Zealand flax, Phormium species) and the non-native aloes (such as Aloe arborescens), which both grow luxuriously in sandy coastal suburbs.
Feeding time
Providing a bird bath, placed away from cover so that cats can’t easily stalk the birds, is another way to encourage native birds. Half-wine barrels — positioned to collect water from a down-pipe, for example — allow bigger birds, such as kererü, to bathe comfortably, and they can come from miles around to cool off in the heat of summer. Leaving bread outside will attract many birds, although they tend to be introduced birds such as sparrows, which may crowd out the native ones. A purpose-made feeder with diluted sugar or honey is suitable for nectar-feeders such as tüï, korimako and silvereye. Please note, though, that the feeder will require regular refilling and cleaning, as feeders can be a way of spreading diseases among birds. Cakes with lard and seed are available to encourage silvereyes. These can be hung from a branch or structure, out of reach of cats.
Encourage insects into your garden
Birds are not the only form of wildlife that should be encouraged into the garden; many insects are beneficial as well. Bees are an obvious example of an insect whose wellbeing is critical to the health of our planet. There are more kinds of insects in the world than there are all other life forms combined and they have the ability to fill many habitats in the garden. However, it is sobering to realise that globally the number of insects is declining owing to human pressures, so it is important that we make a small difference by encouraging them into our gardens. Insects are a key food source for some native birds, too.
Produce
The productive parts of your garden also provide seasonal flowers for insects. Pip and stone fruit produce profuse displays of flowers in spring. Raspberries, strawberries and other berries have a long flowering period and attract prodigious numbers of pollinating insects. Many vegetables are cropped before they flower, however, beans, broad beans, peas and tomatoes are exceptions. A ‘Mediterranean’ garden can include thyme, lavender and other herbs, all of which produce flowers and are very attractive to bees.
The wildflower approach
An increasingly popular garden style is wildflower gardening. Packets of mixed seeds can be bought for this purpose and can be grown as bedding plants. Look for annual flowers that grow and seed well in your area and let the plants seed naturally. This way, you’re pretty much guaranteed winners for your particular location. Examples of self-seeding wildflowers that grow well in most regions include poppies, Cineraria, mullein (Verbascum species), purple Linaria, spur valerian (Centranthus ruber) and shiny Angelica pachycarpa. A useful and easy-to-grow herb is borage, which flowers profusely.
For more inspiration read our article on The Benefits of Biodiversity here.
This is an edited extract, extracted with permission from The Practical Kiwi Gardener, by Philip Thomsen ($45.99, Bateman Books)
