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.....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.
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.