I have been extremely busy lately so that this blog didn’t had a post for the past 2 weeks, in the mean time though a comment came thru from Ian Andrews.
I met Ian a couple of months back at a party and we had a very interesting conversation about the Natural Sequence Farming concept of Peter Andrews (no relations), of which i talked before in a post.
Ian,together with his practice as a media artist, has a property up north NSW and his self directed farming/land managing initiatives brought him to conclusions not far from the Natural Sequence Farming teachings.
I’m transcribing his comment below and updating the page about Pittosporum.
I picked up Peter Andrewsâ€™ (no relation) book â€œBack from the Brink,â€ last week. He makes some good points about the usefulness of weeds but I feel that his methods must be taken with a grain of salt. His practicises might be suited to his environment (Bylong) and for his particular purposes (growing grass for horses), but they should not be taken as universally valid.
There are two problems here: 1. the issue of highly agressive invasive weeds (Andrews refuses to accept this as a problem), and the use of the land (eg. forest, crops, garden, pasture). On my block I have pasture, eucalypt forest and rainforest. The most invasive weeds are in the rainforest. In the pasture the most invasive weed is giant parramatta grass. I am quite happy to grow thistles, patersonâ€™s curse, cobblers pegs, crofton weed, mistflower, paddyâ€™s lucern, introduced sedges, fireweed, and other fleshy weeds in this area but it is absolutely necessary to pull out/poison the giant parramatta grass as it quickly becomes a monoculture. I even let wandering jew (Tradscantia abiflora) grow in this area as it is useful in supressing the giant parramatta grass. In other areas like forest and garden Tradscantia has to be controlled because it quickly forms a dense mat that stops anything else from growing.I have even found that it can be composted (against popular opinion), over a couple of years, in darkness, and then used in lightly infested areas without any problems.
In marginal rainforest areas I will let a number of weeds grow if they are doing a good job of shading native seedlings (wild tobacco in particular). I also tolerate lantana because it keeps the soil moist and can be used to shield native seedlings and as barriers to restrict the movement of feral dogs and cats. But there are a number of weeds in my area that I canâ€™t condone under any circumstances. These are privet, camphor laurel, blackberry and moth vine (Araujia sericifera (horortum)). The seeds of these plants are dispersed by wind and birds and the plants grow in any environment from deep shade to full sunlight. So its not safe to grow them anywhere. The most destuctive of these weeds is moth vine. Iâ€™ve seen 50 or so of these plants smother a small tree and pull it right down to the ground. For this reason it is also called the â€œcruel vine.â€ It has no known use to anything but aphids. The others quickly displace native species.
Another good point Andrews makes is about eucalytpts. In my areas of rainforest I see them as weeds because they introduce a fire threat into an area with a reasonably low fire risk. The more frequently the forest burns the more gums appear until they become close to being a monospecies. I will let them grow if they are providing shade to rainforest seedlings but when the seedlngs mature I use the gums for timber or firewood.
Donâ€™t grow gums around your house. Its asking for trouble. Do grow Pittosporum undulatum. It is not a weed (as is regularly claimed by councils and regen groups) on the NSW coast. The reason itâ€™s growing so well in bushland close to houses is because these places are no longer regularly burnt by the indigenous inhabitants. This is a good thing. It means that the bush in these places (usually south-eastern slopes) is reverting to a more brushy (rainforest like) less fire prone, and more diverse environment. Removing Pittosporum from littoral rainforest an dunes (where it forms an important component of the canopy) is sheer vandalism. Yes Pittosporum suppresses the germination of native (read dry sclerophyll forest) species in dry sclerophyll (eucalypt)forests. But this is not all bad. It is just a sign that these environments are always changing. If we believe that these dry sclerophyll forests, the product of 80000 years of regular burning, are the absolute â€œnaturalâ€ environment for all eternity (this is a common ideology among green goups and scientists) then we risk falling into a very dubious politics: ie. that the original inhabitants are equated to fauna. On the other hand there is really no such thing as a totally natural environment as long as human beings exist and inhabit the land.
Pittosporum has some uses too. The opened seeds can be boiled up to produce a gum. This gum can be used as a safe herbicde on weed seedlings in fragile areas – by smothering the plants. (sugar can also be used for this purpose I believe).
Comment by Ian Andrews â€” February 25, 2007 @ 5:05 pm