Fresh Bark vs Composted Bark

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....The only amedment to his good advise would be that if you choose a bark as an organic make sure that it has started to compost. Bark that is still raw (firm when squeezes of pinched) will rob nitrogen from the soil as it decomposes.
My friend Tom, stated the above in another thread recently. In order not to hijack that particular thread, I have moved his words and my reply here.

I have to disagree with the assumption that non-composted bark somehow is dangerous because the process of decomposing robs nitrogen from the soil for the following reasons.

  • While it is true that when bark breaks down nitrogen is used, this is not restricted to fresh bark only, partially composted bark also breaks down and also uses nitrogen.
  • Partially composted bark actually begins to break down and uses nitrogen quicker than fresh bark. Being already partially composted the decay begins anew once wet and the break down actually occurs at a much faster rate than with fresh bark.
  • I use un-composted fir bark in my soil for all my ficus, a species that prefers a wetter soil than some others. I learned this from Jerry Meslik who originally told me where to buy it at in my area, his success with Ficus can not be debated. Having used this for three years now, I can say from first hand experience that after three years, it has barely begun to break down.
  • On the other hand, partially composted pine bark used in a mix for pines, a drier loving species shows significant break down after the same amount of time.
  • Considering the above and agreeing that decomposing uses nitrogen, logic dictates that partially composted bark used more nitrogen than un-composted bark does.
  • All that is irrelevant however, because the use of nitrogen and other nutrients is a minor factor if you fertilize correctly. Some practitioners are using a 100% inorganic mix (zero nitrogen) and yet the trees thrive because nitrogen and other nutrients are added.

Just my thoughts on the subject.




Will
 

Tachigi

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Walking into the lion's den

Will, I won't bark about your argument on bark ;)

I will try to address your points of debate:

I have to disagree with the assumption that non-composted bark somehow is dangerous because the process of decomposing robs nitrogen from the soil for the following reasons.
I never have said that non-composted bark was somehow dangerous nor implied it. Simply preferences from one to another which I won't repeat again to spare us all from redundancy:)


While it is true that when bark breaks down nitrogen is used, this is not restricted to fresh bark only, partially composted bark also breaks down and also uses nitrogen.
I agree

Partially composted bark actually begins to break down and uses nitrogen quicker than fresh bark. Being already partially composted the decay begins anew once wet and the break down actually occurs at a much faster rate than with fresh bark. .......Considering the above and agreeing that decomposing uses nitrogen, logic dictates that partially composted bark used more nitrogen than un-composted bark does.
I think my point(whether I made it clear or not) in the other thread was that if you use bark, use one that is partially composted because over the long haul it won't absorb as much nitrogen vs raw bark that is starting down the road of decomposition and has a longer time to rob nitrogen. An example would be a mature pine that can stay in a pot for up to 5 years before repotting.

I use un-composted fir bark in my soil for all my ficus, a species that prefers a wetter soil than some others. I learned this from Jerry Meslik who originally told me where to buy it at in my area, his success with Ficus can not be debated. Having used this for three years now, I can say from first hand experience that after three years, it has barely begun to break down.
I won't knock heads on tropicals, because I only have a few and my experience is limited. I will say that your generalization of ficus being a wet soil lover is incorrect. Willow leaf (Nerifolia) in fact likes a good drying before its next drink. I will say that I have repotted (in some years) my Nerifolia twice in a year. Which seems to be what the consensus is from fairly credible sources across the board. That healthy Ficus roots grow exceeding fast and at a minimum need to be repotted every year. So one could conclude that bark won't breakdown nor would it matter if you are repotting this frequently.

All that is irrelevant however, because the use of nitrogen and other nutrients is a minor factor if you fertilize correctly. Some practitioners are using a 100% inorganic mix (zero nitrogen) and yet the trees thrive because nitrogen and other nutrients are added.
Agreed, I have given up the bark habit and replaced my organic with another, sphagnum. Which doesn't break down in the coarse of a potting cycle, and doesn't rob and always gives no matter how long that maybe. It also has added benefits that plain bark be it pine or fir can not do.

So were in agreement Pine bark isn't the greatest composted or otherwise:D
 
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It is true that you never said that non-composted bark was somehow dangerous, you mentioned that it uses nitrogen to decompose and warned againsr using it. My point was that composted bark also uses nitrogen to decompose and actually starts the process faster.

As to sphagnum moss, I agree, it is greatly under utilized in bonsai.

No den of lions Tom, just digging to find the gold. ;)


Will
 
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This is a hot topic that will be debated until the end of time. We have been taught to use organics because Naka-san taught so. Other soil recipes, in fact traditional Japanese recipes, have been shown to produce phenomenal results over and above what Americans have been making do with for decades. There are always exceptions, but I cannot say that tropicals or ficus are or are not an exception to that rule.

And it's true that it's hard to argue with Jerry Meislik's success with and knowledge of ficus. My own preference for all my trees is Boon's mix, which is simply a traditional Japanese mix of akadama, lava, pumice, a bit of charcoal, and a bit of decomposed granite. But who can find decomposed granite in Kansas? So I tweak it and replace the granite and pumice with our local haydite. It's not the best solution but it works pretty well for my trees.
 

agraham

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Boon's mix seems to be very popular with his followers.I wonder if it is because it is what he uses and recommends and antecdotal evidence as opposed to genuine research.I won't argue that it is not a great media,because every evidence that I have seen shows that it is...but I am curious as to what each ingredient provides that is lacking in the others.

I don't think that any organics are necessary in a good media.Until they are well composted to a particle size that is detrimental to drainage,they probably all rob the plant of nitrogen.I would imagine organics provide some microbial action that is lacking in nonorganic aggregates.But then if organic fertilisers are used,this would be a moot point.They are certainly more moisture retentive(in most cases).

All in all...I guess that there is a tradeoff of good and bad in every mix depending on how one choses to water and fertilise.

andy
 
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All evidence is anecdotal to some degree. We tend to overanalyze sometimes. CEC doesn't mean so much to me except as a chance to argue. However, Boon has students and clients in almost every climate zone in the country, and trees thrive in his mix everywhere it is used. That's why his students put so much stock in it.

As to what each provides, who really knows for sure? Lava is very porous and sharp-edged. Pumice is far less so but still provides structure for the soil. Akadama seems to be better at what it does than any of the substitutes, although its main drawbacks are cost and the need to repot every two years (for the softer version).

All of this has to be balanced with the capacity to water more than once a day! For those of us who work for a living, this type of mix absolutely requires a reliable automatic watering system or well-trained apprentice.
 

Rick Moquin

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A section of Brent's Blog:

The fir bark I use is fresh, the fresher the better. You want your soil mix to retain its particle nature, and fresh bark will last longer than composted bark, which already has one foot in the grave, so to speak. Don't worry about nitrogen lockup, it is a negligible factor for bark. You can read more about that and many other factors in the article on Soils at my website. And yes, I have checked with a plant pathologist on the use of fresh bark, and studies indicate that the volatile chemicals in fresh bark have some anti fungal characteristics and don't otherwise impede growth. Anyhow, I have been using it for twenty years as well as many of my fellow nurseryman.

I believe that the prevention of soil collapse outweights any nitrogen loss. A soil that does not collapse will remain oxygenated longer, which is the chief ingredient is posperous growth.
 

grouper52

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I would imagine organics provide some microbial action that is lacking in nonorganic aggregates.But then if organic fertilisers are used,this would be a moot point.They are certainly more moisture retentive(in most cases).
My own experience, and I have heard and seen this from others as well, is that pure inorganic soils give rise to incredibly vibrant growth of mycorrhizae compared to soils with organic components as well.

grouper52
 

agraham

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My own experience, and I have heard and seen this from others as well, is that pure inorganic soils give rise to incredibly vibrant growth of mycorrhizae compared to soils with organic components as well.

grouper52
Interesting,and I have heard of and seen this too.I wonder if it is a function of the organic fertiliser used or independent of any organics(excepting decaying roots).

Just to be clear though....microbial activity is not limited to mycorrizae.

andy
 

agraham

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Since mycorrhizae are fungal in nature?
Interesting point Chris.Most fungicides are somewhat pathogen specific though.I wonder if this might not be the secret to the purely inorganic mixes and their seemingly incredible mychorrizae colonization.

andy
 

Tachigi

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or well-trained apprentice
LOL.....dam I'm screwed. I took a vow of poverty when I got into this business
 

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