It is important to have some sort of plan before beginning to develop your wirra. Too often I see someone, with the best of intentions, clear weeds from their block only to watch it return to a worse state than it was before.
Recently I watched a neighbour clear an exotic pine forest. Before it was cleared it was reasonably clear of any vegetation under the pines. It would have been so easy to have assisted its return to something delightful. Instead they simply left it alone to become whatever it wished. It was an interesting exercise. Firstly a mixture of indigenous natives and exotic weeds germinated. At that stage it would have been relatively simple to remove the exotics as they sprouted. However, they were left to flower and seed. Within a few years the block was nothing but introduced weeds. The indigenous natives were drowned out by the imports. Now the block is worse than it was before the exotic pines were cleared.
The point here is that any species of plant, given ideal conditions, can become a virtual monoculture. Since each species of plant evolved to fill a special niche in nature, given those conditions that plant will take over. It is therefore important that anyone contemplating developing a wirra understand what they are doing.
The steps are fairly straightforward.
Understand which plants grow in your area and which of these are indigenous. There are usually a number of books devoted to your region on this point. For the Adelaide Hills, for example, there is “Plants of the Adelaide Plains & Hills” by Dashorst and Jessop.
Make a list of those plants which grow on your block with a note of whether they are desirable or not. Keep this list up to date.
Work out how you are going to measure success or failure. It is much better if the time you spend in your garden achieves the results you hope. The measure that I use is simply how many species of indigenous plants are occurring on Wirrapunga and how many of each.
It is very important that you do not try to do too much at once. If you remove some weeds then you will be met with a mass of new weeds. It is imperative that you can handle the replacements or you may be actually worse off than you were before you started.
It is a good idea to start at one spot on the block and always make sure that you are on top of that area before you move on to the next. I always start at the top of Wirrapunga and work down to the bottom. It was five years between when I started and got to the bottom for the first time.