Permaculture Information Web

[Robyn Williamson <rz.williamson AT optusnet.com.au>]

On Friday, January 28, 2005, at 04:02 am, Stephanie wrote:

> Thanks for the wonderful feedback, Robyn.
> (Are you the Robyn I corresponded with a while back?
Welcome!)

err ... i don't think so ... it must have been the famous Australian 
scientist Robyn Williams ... but thanks anyway Stephanie
(just kidding - yes, it's only me;-)

> You asked, "Also, would it be possible that if we enter a species name
> for example, we get all the plants in the family?  Many may be 
> compatible
> with each other and it could be a first step to making a guild,
> especially if it's only physical characteristics we are combining into
> the guild (height/width etc) e.g. ground cover, with shrub, tree and
> vine."
>
> Certainly.  However, many plants in the same family share the same 
> pests,
> etc.

True, they do, and the example I gave was maybe not good, it was just a 
thought.  The purpose of plant families is in identification of the 
relationships between groups of plants.  The information is not 
geographically confined and applicable in any region despite 
adaptations or variations brought on by climatic and other influences.  
You rarely find plants in the same family that would fall into all four 
categories of ground cover, shrub, tree and vine anyway, except some of 
the really big families, but herbs together with ground covers, shrubs, 
trees, bulbs and vines creates "stacking" or vertical edge, saving 
space and helping to keep out invaders.  That is what I understand a 
guild to be, i.e. a collection of mutually beneficial plants;  but what 
is a pest?  Many people would think of fungus as a pest or disease, 
however most vascular plants rely on mycorrhizal (fungus-root) 
associations.  They may even be communicating with each other in this 
way, who knows?  Fact is, you rarely get things like pests and diseases 
in healthy natural systems and that is what we are aiming for, n'est-ce 
pas?

> To my knowledge, we will be organizing/sorting plants on a Pc-
> characteristic basis (including functions satisfied, pests, and
> otherwise).  Accordingly, if you are searching for compatibility, you
> would not necessarily (or only) get plants in the same family (unless 
> you
> specifically chose to),

Sounds good - so we search for the species if we want to find out the 
family, and then search the family to return the full result.  Also, 
instead of using words like pest, disease, weed, etc, I for one would 
prefer to see a simple term like "known problems" and for 
Pc-characteristics perhaps "Uses - culinary/medicinal/other"?  With 
plant families, genera and species, botanical taxonomists often 
re-classify and/or change names to comply with the International Code 
of Botanical Nomenclature as new information comes to hand.  What does 
the piw do with synonyms? because firstly we must be sure we are all 
talking about the same plant [that is the purpose of international 
nomenclature] and only secondly about whether or not we are able to 
lessen the confusion for people IMO.

> but plants from other families that might be
> considered 'companion plants.'

Excellent, that's what I was hoping for.  A good evidence-based read on 
this topic is "Successful Organic Gardening" by David R. Murray (2000), 
Kangaroo Press/Simon & Schuster Australia, 20 Barcoo St, East Roseville 
NSW 2069, pp. 18-24.  In Chapter 2 Dr Murray takes on the difficult and 
myth-laden subject of companion planting and even refers to most of 
what has been written as "derivative nonsense or misguided invention".  
Here is a quote from p.18:  "Competition and co-operation are the key 
ecological principles fundamental to human understanding of the ways 
plants live with one another, and with other organisms.  These 
principles are not mutually exclusive, and many apparently competitive 
or parasitic relationships are symbiotic in a broader sense.  Take 
cicadas for example.  Their dependence on the roots of trees to provide 
total nutrition during the nymphal stages is at first sight parasitic.  
But is it really?  As spring arrives, the maturing cicada nymphs drill 
new tunnels through the soil, right to the surface.  The ground near 
host trees becomes literally peppered with small but obvious holes.  As 
a result, air is carried to much greater depths below the soil surface 
than usual, improving the availability of oxygen [and water ... R] to 
the whole root system.  This is a major benefit to these trees at a 
time when the potential for growth rate to increase is raised by 
increasing temperatures ..." ... "Are ... [they] ... always purely 
competitive?  The answer is often no, and the simplest view of 
companion plants is that they are plants that help one another when 
grown together ... perhaps better than either would do alone ...  
conversely, there are plants that seem to antagonize one another such 
as basil and rue, or beans and fennel."  Then there are plants known as 
allelopaths which allow nothing else to grow near them.

> Furthermore, organizing the plants on a
> Pc-characteristic basis would allow for *substitution* of plants - 
> which
> would be very useful.

Indeed!  When I can't find a specific plant I look for it's closest 
relative.  But if I'm looking for "cloves" for example, would I also 
get things like Dianthus that have a similar/substitute taste?  In this 
case we are looking at the difference between a tree and a herb/ground 
cover.

According to Dr. Murray, the following is as true for strawberries, as 
it is for apricots, cherries, nectarines, peaches and plums (all, 
including the strawberries, are in the same family) and I would 
therefore not hesitate to conclude that it would be the same for 
almonds, apples, pears and quinces (which are also in the same family). 
 But nettle isn't.  Misguided invention? you'll never ever know until 
you have a go, or trust someone who has.  Dr Murray adds:  "Does the 
stinging nettle gain anything from these associations?  Even if it 
gains nothing but space, it is doing well in a competitive world".  
Fact is if I could handle all that nettle I would grow it with just 
about everything because of its beneficial interactions with the soil.

"The strawberry grows underneath the nettle,
And wholesome berries thrive and ripen best
Neighboured by fruit of baser quality"
William Shakespeare
Henry V, Act 1, Scene 1

I suppose it depends on how professional we want or need to be in 
individual cases, but one thing's for sure - anything less than 
scientific permaculture will give us all a bad reputation in the long 
run because we can so easily be proven wrong.

Best regards,
Robyn

CONTACT DETAILS:

Robyn Williamson
PDC, Urban Horticulturist
Hon Sec, Fagan Park Community Eco Garden Committee
Local Seed Network Coordinator
NORTH WESTERN SYDNEY COMMUNITY SEED SAVERS
mobile:  0409 151 435
ph/fx:  (612) 9629 3560
email:  rz.williamson AT optusnet.com.au
http://www.communityfoods.com.au
http://www.au.gardenweb.com/directory/fpceg
http://www.seedsavers.net/lsn/32.html
http://www.sydney.foe.org.au/water