I've done so much whining about commercial compost in these forums, it is now overdue for me to write a web page about it.
But ... I'm short on time today ....
A quick list:
wood chips are in nearly all commercial composts. They are usually (at least around here) conifer. The upsides outweigh the down sides, but it is good to know the all the issues. Conifer wood chips are acidic and contain stuff that will make most plants sick. But since they are usually in a mix with manures, your grass will green for a few weeks due to the manures before yellowing due to the wood taking up any excess N in the soil. As the years pass, the wood chips will slowly break down and re-feed that N to your soil and the stuff that makes your grass and other plants sick will fade in time.
So, there are short term bennies and long term bennies. And there are short term down sides.
And this just has to do with the wood chips.
Next up: to my knowledge, all commercial compost contains residual pesticides. I know that "all" is pretty bold, but this is something I've done a lot of reasearch on and the results have been freaky. I hesitate to say all, because I cannot possibly know of all. And so I leave this as an open challenge: anybody know of even one that doesn't?
The big residual pesticides are clopyralid and picloram (found in tordon). These have a half life of 11 years and 7 years respectively. If you decide to grow a garden later, you might have trouble. Or even if these pesticide levels are low
enough that you can grow a garden, it is possible that your garden won't be as lush, or might be susceptible to disease and bug trouble.
Then we can talk about the manures that are generally used in the composts. This leads to discussions of what medications that might be used (most commercial wormers will pass into the manure and kill earthworms and other soil organisms), and what sorts of toxic gick those animals ate that was passed through and will bring you grief (most pesticides pass right through).
So I have about ten times more to say on this topic and can probably say enough to freak anybody out right to the core. So .... what to do? How do you build organic matter if you aren't going to use commercial compost?
My
answer to that is even bigger, and I still don't have the time for this sort of thing. I think patience combined with organic fertilizers and leaving the clippings is some of the best. I could spend a week waxing on about lawns in a
permaculture setting thriving better than in a monoculture setting. And then there is good ole clover in the lawn. And .... I would really like to try some of the stuff from
fungi perfecti. And recently I saw something about EM: I would really like to learn more about that stuff: I'm both hopeful and cautious.
I hope that this answer isn't too freaky annoying.