Strategies for developing a (Mediterranean climate) Permaculture Plant Palette — Part II
Our goal is the development of a palette of plants which can be used to develop permaculture systems which are sensitive to the climates they are in. In the last post we looked at developing the scope of our palette. In this post we will look at ways to limit that scope to the plants to the plants with the highest degree of utility for a permaculture system.
So far we have the set of plants …
… native to your area,
… native to places within similar climatic zones to your site,
… that possess adaptive strategies required for life in your climatic zone, and;
… plants that provide specific desirable yields.
This is a very large set of plants — too large for design without a very good plant database tool.
We will now consider how to sift this very large set to get that set of peculiarly useful plants for inclusion within a permaculture design.
Consider priority ecosystem functions
An ecosystem function is something an ecosystem requires for its maintenance or flourishing. Ecosystem functions include things like:
habitat (for insects and other animals)
All of these functions are important for our permacultures. When they are considered together, they are a very powerful selection tool. If we consider the permaculture principle that every element of a system ought to have multiple functions, our list of possible plants can be made rapidly smaller. We might, for instance, prioritise those nitrogen fixers which also provide pollination support and weed suppression and so diminish our list of potential nitrogen fixers.
Consider potentially troublesome plant qualities
Permaculture practicioners often shy away from the use of words like 'weed' but some plants in some conditions are just plain undesirable. They may:
tend to rampancy / be opportunist in nature (secret: this is ecological code for 'weed')
be poisonous to humans or animals
check the growth of other plants using growth inhibiting chemicals (allelopathy)
have thorns or prickly leaves
Let's consider the nitrogen fixers in our expanded palette again. Many nitrogen fixers tend to rampancy — they have a distinct advantage over other species in nutrient-poor conditions in being able to supply their own nitrogen. As was noted in the last post, Western Australia has many native nitrogen fixers so we may prefer to use only natives for this function. We may then realise that Acacias can induce hayfever in some people and so determine to use mainly Casuarina spp. for nitrogen fixation (leaving aside their potential for allelopathy for the sake of an example). Each of us will have different parameters but it is certainly a good idea to ensure that you're not going to introduce a nuisance to your area.
A pretty obvious point but its easy to get carried away thinking about plants from other places which can be very difficult to find locally. It's not much use designing your system around plants that you can't (easily) get hold of. This will mean different things to different people. If you're the propagating type then made sure you can get hold of plant material. If you're the buying type check what your local nurseries can get in and what you can get by mail order or via the internet.
Consider regional ethnobotany
Ethnobotany is the study of the relationship between plants and people. One of the ways to find useful plants within the scope of our palette is to look at how people in the places from which we have drawn our palette use the plants from their area. This might lead us to consider cultural plant use in space and time. For example, for south west Western Australia, we might consider Nyungar plant use (eg. Acacia spp. seeds for flour) in adition to contemporary commercial horticulture / agricultural plant uses. We might also consider historical and contemporary plant uses for mediterranean climate zones of Chile, South Africa, South Australia, California and the Mediterranean basin.
Everyone who follows these steps will end up with a different set of plants. This is the beauty of a permaculture — unique solutions for every place, from climate to household. What we have developed here is something between the kind of list of species that a designer might use for a range of sites in a particular climate and a list of species suited to a particular site. These are a few of the strategies I use to think about plants for a permaculture. There are more but I didn't want it to sound too scary. I've probably already made it sound like that. Its probably best to consider the strategies in both posts all together and keep checking them against one another. I'd be really pleased to hear your thoughts on finding the plants most appropriate for a particular climate or site.
