nedwina McCoy

Jonathan_Byron wrote:
When something is labeled a "troublesome weed" that almost always reflects a world view rather different from my own...
http://www.nytimes.com/2011/04/03/opinion/03Raffles.html?_r=2&ref=todayspaper

Species die off and are replaced all the time.  Life on the planet is not unchanging.  I don't refute that.  Not at all.  But the manner & speed in which our native species are endangered or dying off, due to habitat destruction from various reasons, (perpetrated largely by humans) is not happening at a pace where Nature can correct.  Predator/prey relationships build over centuries, not over a few generations.  Even when there is a substantial event that wipes out an ecosystem, the survivors and newcomers (and their corresponding predators) are from the general area- not from another continent.   

Certainly there are introduced species (exotic or otherwise) which have little or no impact on native ecosystems.  Or even observable beneficial ones.  Those were Happy Accidents.  And are handy to point out when this discussion occurs.  But the comparison between them and Invasives is apples & hand grenades.

And today's benign non native can become tomorrow's destructive Invasive should conditions change.  Which they do, all the time.   

There is this attitude (whose foundaton can be found in Genesis too, BTW) that we humans can do whatever we want, whenever we want, and Nature's systems will adapt and continue to provide for us.  And there weren't many indications to assume otherwise, for centuries.  But here in the Modern Age, with the global exchange of flora, fauna, bacteria, fungus, etc., it is becoming clear that we can't reshuffle & redesign Nature (by accident or whatever) on a global scale without consideration and expect her to accomodate our hubris.  There are consequences.  Some pretty serious ones. 

Maybe you don't see Invasives altering your ecosystems in your backyard, but I do.   I spend tremendous time, energy & money trying to keep them at bay.  If I don't, my native food chains will suffer, and I, the resident human, will suffer also.  If you ever find yourself in the Northeast, drop me a line and I'll give you a personal tour and show you what I've learned first hand.

H Ludi Tyler wrote:
Are mimosas destructive?  And in what way?    They are quite beautiful trees and I've not seen anything like solid stands of them - they seem to be scattered through the forest.

It depends on where you are.  Mimosas/Silk trees (Albizia julibrissin) is "regulated" in TN, and a "troublesome weed" in FL.

http://www.invasive.org/browse/subinfo.cfm?sub=3004

If you do a search on "Albizia julibrissin invasive" all kinds of links pop up.  Invasive status is largely decided on a state level.  And can be very political.

maikeru wrote:
What you're discussing does mainly apply to green manures and a huge N boost that heavy nitrogen feeders or grain crops require. This is a different situation. When using N-fixers or N-fixing trees, N is lost in appreciable amounts and absorbed by the surrounding area due to litter fall, biomass removal (leaves, branches, stems, tops, etc.) for composting or mulching, root die off and turnover, browsing by animals and their waste deposition, humus building, etc. N added in this way is mostly and gradually cumulative within the system, whereas killing green manures or coppicing produce large pulses of ready N and C into the system, which become available to the following (annual) crops. Perennial crops/forest don't generally require such large pulses of N, since they usually have lower N requirements and a bank of nitrogen already built up in humus, litter fall, etc. in the soil. Too much N and basically all you end up with is leaves, not fruits or roots. That's fine if you want to grow leafy greens and annual grains, since they live fast and die young. Not fine for orchard trees.

Edit: I wanted to note also that killing green manures and plowing them under is not really mimicking natural systems, either. And second edit: others posted while I was writing my original post, so apologies for the redundant info.

Understood.  (Well, sort of, LOL.)  Seems to me that the killing & plowing under of green manures is a deliberate manipulation & acceleration of the natural N releasing systems you have described there, no?  But certainly the point is to have it happen on its own, at a slower pace, and in measured amounts suitable to perennial crops.  

Jonathan_Byron wrote:
The term 'invasive' is one that is invented and applied by humans. The use of this term is sometimes accurate and valuable, but can also be biased and arbitrary.

When a cleared field is abandoned, it is pioneered by species which grow rapidly and release lots of small seeds that travel long distances. Are these not 'invasive' in many ways? But if they are the invasive species that people are used to, they are not labeled negatively.

Sure, introducing a species into a new niche can be disruptive - kudzu, fire ants, and many other species demonstrate that when a species is moved to a place without the natural pests and controls, it can be very successful (at the expense of other species). 

In the original post, da_wanderer noted that there are already mimosa trees all over the place... in that case, one is merely using plants that are already present. If one lived in a place where there were no mimosa trees and there was reason to believe that they might thrive and get 'out of control' then one should think hard about the wisdom of introducing it. But if they are already there and running rampant, the impact of growing them is not so great, IMO.

The term "invasive" is often misused.  But there is an official definition.  All it takes is a quick search to see that Mimosas are considered an Invasive species by the USDA and by various state authorities. Granted, in some locations they are more prevalent (and destructive) than others, but I fail to see your reasoning in this statement:

But if they are already there and running rampant, the impact of growing them is not so great, IMO.

I don't subscribe to such a philosophy.  But perhaps it is because I am constantly battling Invasive species on my property, and have witnessed their destructiveness first hand. 

Permaculture by definition is supposed to be "sustainable" and based on "ecological relationships"...there is nothing "sustainable" about Invasive species, and since they destroy native "ecological relationships", why would they be included/condoned in Permaculture?  I simply don't get that.   

H Ludi Tyler wrote:
What if you coppice the nitrogen-fixing tree just as it begins to set seed?

It'll stop seed production, but won't have any effect on releasing the N sequestered in the root nodules. 

Coppising is great if you want to encourage sucker production for raw materials.  Making baskets, stakes, etc.  But from a woodlot maintenance point of view, unless you keep up with it, (forever) you'll end up with multi trunk trees which are hazardous (water collects in the crotch & rots the bases) and difficult to cut down safely when you do want the lumber....

http://en.wikipedia.org/wiki/Nitrogen_fixation
http://en.wikipedia.org/wiki/Actinorhizal_plant

If you want to read about N fixation presented in understandable layman's terms, I can't recommend this book too much: http://www.johnnyseeds.com/p-7976-northeast-cover-crop-handbook.aspx  (You don't have to get it from Johnny's it's available elsewhere.)

First a word about N fixation: with cover crops, accessing the fixed N does not happen unless the plant is killed in a timely fashion.  N fixers are fixing N for their own use, and you have to destroy the plant before blossom, and especially before seed set, to access/release it best.  If your N fixer has set seed, it has prettymuch used up the N in its nodules. 

If there is plenty available N in the soil, N fixers will be lazy, and not fix N from the air and will not form the nodules.  So if they do use the available N from the soil, and complete their life cycle, you may actually be looking at a net loss of N in your soil.  It is now in the seed.

The idea of utilizing N fixing trees doesn't make sense to me, unless those trees are remarkably different from green manures.  But from what I can tell, they're not.  Except that their natural life cycle is considerably longer.  N fixing trees can pave the way for other N needing species to grow in a given location, but the process is slow, transitional, and dependent upon the N fixers dying and creating new soil composition over a long time as they break down. 

Since Permaculture is supposed to be a controlled mimic of natural biological systems, the use of invasives seems contrary to me.  The only role invasives play in native ecosystems is a destructive one.  Planting invasive trees expecting to reap & take advantage of their N fixation, without understanding the manner in which N fixers work, (how death & time plays a key role in making that fixed N available) sounds counterproductive.  Over the life of that invasive tree, (unless you grow & kill them over & over) it's going to send out billions of seeds... and it's not guaranteed that any appreciable amounts of N will be gained from its being planted when it eventually dies a natural death.  But plenty more invasive trees will be gained, spread far & wide from that mother tree... 

Scott Reil wrote:
One of my moderators just logged in and told me that here terrible infestation, that just spinkling was heading back some, but not completely killing off, has been corralled by a cinnamon/chamomile tea she made (chamomile is a low grade antifungal). She just put cinnamon sticks and tea bags in a jug, kept refilling and changing out the herbs and spices as they seemed to lose efficacy, and watered the soil (not the plants). She is fungus gnat free and swearing by this method...

Another sure fire method is nematodes (Steinernema feltiae being the most effective and best for indoor use on FG's). Predators are always a green fix, and a good link in the poop loop.

And I'll keep the cinnamon tea method in mind.  That might be a good use for those stale sticks you find in the back of the cupboard. I looked into the nematodes, but the amounts available & the price were too much for my small area & wallet.  (Same with Gnatrol.  Yow!)

So long as it's 3% drugstore H2O2, and you keep within the 4-6 oz range per gallon,  it should not harm the plants.  I keep alot of cuttings overwintering under lights in the basement (AB basil & coleus, geraniums, fuchsias etc.) and have a fair amount of standard house plants (plectranthus, ivies, pothos) and have never had a problem.

Be advised though, that it's not a one dose cure all.  You have to keep using it for a few weeks, and after you think they're all gone & stop using the mix, suddenly one or two will show up out of nowhere.  Thankfully H2O2 is cheap and readily available.

I frequently load up on the skeeter dunks in late summer.  They're kinda hard to find midwinter. 

Glad to help.  Good luck.

ETA: (Oops.  This was intended as a reply to Jessica.  My bad.)

If the cinnamon method doesn't pan out, 4 oz of hydrogen peroxide to 1 gallon of water does the trick.  Mix up a batch & use it every time you water- it won't harm the plants. 

I also grind up those skeeter dunks (which has the right kind of Bt) and throw about a tablespoon in a gallon of water & use that if the infestation is mild.  The bits will stick to the sides, but that's ok- if it dries out, fresh water will reactivate the Bt.  I don't bother cleaning out the gallon containers, I just add more periodically & give it a good shake.

I just got over a tremendous infestation and had to bump up the H2O2 to 6 oz/gallon.  From "play sand" that I was storing beets in.  Unbelievable amounts of fungus gnats.  Totally gross.  But after dumping the crocks & treating the plants for a few weeks, they're all gone now.

http://www.umass.edu/umext/floriculture/fact_sheets/pest_management/fungnat.html