9th February - Maintenance

Maintenance is about maintaining the status quo. When you commence a bush garden you start by removing exotics in some sort of order. The idea is to remove the species which cause the most damage first and proceed until all exotics have been removed. Of course you probably never get to that stage because there will always be weeds, of some sort, in all gardens.

Anyway once you remove a species then you must make sure that you keep removing it. So you have a list of species that are the first to be removed at all times. Suppose you start by removing the introduced pine trees from party of the bush garden. Then introduced pine trees would be at the top of your list on what must be removed if they return, as they surely will for many years. You may then remove introduced woody weeds such as blackberry, broom, gorse, etc. These are added to your list. Therefore at any stage in developing your bush garden you have a "hit list" of plant species that are simply not allowed in your bush garden. My hit list is now some 70 species and growing, although much more slowly now.

The first part of maintenance in a bush garden is the removal of weed species which are under control but will quickly multiply if allowed. History has already shown you this.

However even if you were able to permanently remove all the exotic species in your bush garden then it would still require maintenance. Since the events which kept the bush healthy and vibrant no longer occur, the biodiversity will gradually disappear if it is now left to itself. In short indigenous woody weeds will take over.

While you are actively removing weeds then this, in itself, is probably creating enough events for your indigenous plants to thrive. However, as this sort of event decreases as the weeds become fewer and fewer another sort of event is needed.

I find that a good mower, set at its highest level, does a magnificent job. It needs to be done about every five years. There are pitfalls however. There are plants that because of their rarity need to be left. It would be indeed foolish to mow down a plant you have just spent years encouraging if this may destroy it.

It is a good idea to mark special plants, you would prefer to leave, so you can see them. For example in the first area at Wirrapunga, that had become basically weed-free and there was a distinct decline in biodiversity, there was one Cheiranthera alternifolia plant. I left it, but mowed around it. Five years later, when I mowed again, there were three of them which I left. Today there are about ten of them.

Of course there is a time of the year to carry out this chore. Remember you are imitating a mob of grazing animals or a bush fire. I like to do it when my indigenous plants are hibernating in the middle of summer. I think February is probably the best time.

Finally it must be remembered that your mower has the potential to do more damage than good. If you have previously used the mower in an area which is not weed free then it is probably carrying weed seeds. If you now mow your pristine bush without cleaning it properly, you are doing two things. Firstly you are creating an event which is going to encourage seeds to germinate. Secondly you are spreading weed seeds ready to be encouraged to germinate. The message is - make sure your mower is free of weed seeds before introducing it to a weed free area.