Over the years when I have posted about a disease or pest problem I have occasionally had someone make a comment inferring that I am having this particular problem because my garden is “out of balance” and that if my garden was “in balance”, I wouldn’t be having the problem.
So are people making such claims right? Well I think that they are both right and wrong, but I mostly wrong. This post explains why I think this is the case.
“The balance of nature, also known as ecological balance, is a theory that proposes that ecological systems are usually in a stable equilibrium or homeostasis, which is to say that a small change (the size of a particular population, for example) will be corrected by some negative feedback that will bring the parameter back to its original “point of balance” with the rest of the system.”
SOURCE: Wikipedia
While it is possible to create a sort of ecological balance in an urban garden there are a number of factors in play that limit just how much balance can be obtained. Below is a brief summary of some factors that make the concept of an ecologically balanced garden extremely difficult to achieve.
It has been said that when a road is built in the Amazon jungle it directly affects the ecosystem for over a kilometre each side of the road. These roads bring plants, animals, insect and even just plain sunlight which profoundly changes the ecological balance of the jungle in the immediate area. If a single human made road can have this impact than a suburb, which is entirely made by humans can only ever have a tiny remnant of a natural ecosystem. Photos courtesy of the internet.
You might have a garden that encourages natural diversity but the properties surrounding you are more likely to have lawn based (sterile monoculture) gardens and/or regularly spray with powerful chemicals that destroy insect diversity in their backyards. Chemical spray drift from neighbours spraying may even fall directly onto your garden. Dogs and cats also have a negative impact on wildlife such as birds, possums, frogs and lizards. Even if your neighbours do have more biodiverse gardens the fact that roads and houses take up to 60% of the available space (even higher in new suburbs) in an urban environment, which leaves little space for a garden no matter how biodiverse it is. Image Courtesy of the internet.
There is no vegetable grown by humans that has not been genetically altered by breeding. They have almost all been bred for flavour and size, often at the expense of resistance to diseases and pests. In addition the original wild versions of vegetable plants would have had a relationship with other plants, insects and animals in their original habitat which are not present in the suburban backyard. Given these factors today’s vegetables are always going to be more susceptible to pests and diseases than their original wild versions, making it harder to create a natural balanced garden.
While all the above is true there are a number of things you can do to make your garden more biodiverse and therefor create a healthier garden. Below are suggestions as to what you can do to increase biodiversity.
Planting a wide range of flowering plants (both exotic and native) will attract a range of insects, animals and birds, all of which will help improve biodiversity in your garden.
Providing plenty of cover for birds and small animals like frogs and lizards will make it easier for them to hide from predatory animals such as cats.
If you have some ponds in your garden it will attract birds and beneficial insects such as dragonflies. If there are frogs in your area they will be attracted to your garden and may well breed in your ponds. To discourage mosquito larva stock with small fish or inoculate your ponds with water from a nearby pond or swamp. Such water will contain tiny predatory insects such as mud eyes (dragonfly larva), damselflies, water scorpions, backswimmers, and water bugs, all of which will eat mosquito larvae.
This photo shows two of four bathtub ponds that I have in our garden.
Regularly placing mulch on your garden will help create a healthy subsoil for bacteria and worms. Healthy soil increases the chance of healthy plants and healthy plants are more resistant to pests and diseases.
Accept biological diversity of all kinds even if it is classified as a pest and does damage in your garden. I never destroy blackbird nests when I find them and these days I only ever kill snails when they are directly on my vegetable beds. Both these animals are part of the jigsaw puzzle that is a biodiverse backyard and can have a positive impact, even if it is not obvious.
below some examples of biodiversity in our garden.
TOP LEFT: One of the resident wolf spiders. TOP RIGHT: A Ewing’s tree frog on a raspberry leaf. BOTTOM LEFT: A young pobblebonk in one of our bathtub ponds. BOTTOM RIGHT: A stick insect. My hand in the photo shows just how big it is.
The flowers of this waxflower plant attract a myriad of insects including hoverflies (look like a tiny bee). Hoverflies are very beneficial in a garden as while the adults feed mainly on nectar and pollen, the larvae (maggots) eat a range of small insects including aphids. So attracting hoverflies to your garden is very beneficial. When there are large numbers of hoverflies in our garden the aphid numbers are usually low.
Urban gardens are way too small to create a long term balanced ecosystem but by having as much biodiversity in your garden as possible you will create a healthy environment for its plants, insects and animals and will reduce the risk of big imbalances occurring. Besides, your garden will be visually more pleasing.
