composting pine bark

Provo, UT(Zone 5a)

i cant find a forum thats brought this if i missed it
please forgive my reposting this..
i will always do my regular compost.. :) from my readings..use of
pine/fir bark fines seems direction im going..
and from my readings..maybe theres a benifit of using composted
bark slightly over "fresh" bark..
now my understanding is..chips/fines of bark..not just wood.. yes..???
the bark decomposes much slower,has chemicals that repel bugs ,
and isnt tying up just wood chip would..??? yes??
so?? my main question.. do u all think composting bark would be
worth my time?? if thinking..just adding needed nitrogen,and
water..and turning would do the job..??
hope to see some thoughts on this..
much thanks !!!

Everett, WA(Zone 8a)

As far as I know, everything you're saying is corect, but what do I know? I hope more people chime ikn.

>> the bark decomposes much slower,has chemicals that repel bugs ,

I didn't know that the waxy suberin repels bugs. Great! (Termites, at least.)

I know that it repels water, which is one reason bark shreds hold less water than peat. Of course, even bark FINES are coarser than peat fibers. And you van get coarser bark, up to nuggets and large nuggets suitable for growing orchids.

Suberin also makes the bark break down much slower than wood of a similar size.

>> and isnt tying up just wood chip would..??? yes??

LESS than wood does, because it breaks down slower. I've read recently that it DOES take up some nitrogen temporarily, and that's a reason to compost it before turning it under, or use it as bedding for animals, or add ammonia, or use it as mulch long enough for it to break down (a LONG time!)

I'm researching this right now, and it is confirmed in a PDF from the U.S. DEPARTMENT OF AGRICULTURE - FOREST SERVICE

They say:
"bark does not attract and does not provide nutrients for termites;"
"does not attract nematodes or termites."
"Beneficial effects in depressing soil-borne plant diseases have been observed."
"Bark tannins ... help retain important minerals in the soil; they also complex with soil nitrogen compounds and prevent their rapid breakdown or elution."


"the benefits that it can confer on poor soils as a soil conditioner are appreciable. It lends body to
sandy or silty soils, yet loosens up clay soils: bark can improve the tilth, structure,
and aeration of heavy soils, and increases water absorption and penetration.
It has a high ion-exchange capacity and, except for nitrogen, contains all
the nutrients necessary for a good organic soil. As a mulch, it conserves moisture
through weed control and reduced evaporation; it maintains uniformity of
the soil and improves granulation of surface soils; it reduces topsoil erosion,
and builds up organic matter and humus in soil with concurrent benefits to the
soil microflora."


"A related use of bark is as a potting medium for container stock and for rooting
plant cuttings (45,50-52,75,76,88,119,122). Several companies are marketing
bark for this purpose."

Anne Arundel,, MD(Zone 7b)

I'm glad to read all that, Ric.
But my gut feeling is- just mulch with the bark and let it eventually become part of the soil. Won't it sort of self compost?

Actually- since bark resists rotting, why try to compost it? Doesn't compost imply trying to rot something as fast as possible? It feels like to me this is trying to fight the nature of the material, when you could use the bark for its benefits as mulch first.

Having stared at tons of slow compost that "should have" rotted more quickly, I just feel like trying to compost bark is going to be pretty unrewarding. THats my two cents!

PS bark fines as potting soil amendment is much cheaper than 'potting soil' though. Thats what I'm using fines for- makes potting cheaper and better.

Provo, UT(Zone 5a)

thanks sally and rick.. good stuff..
sally thats why i was thinking in composted bark..if why i want
the fines in my pots..better drainage,cheaper,why not just use
uncomposted fir bark fines..
here..size tapla has pointed out so many times.
similar size in pots as much as possible..not clumping up the
air spaces in the pot..and hindering the drainage..which is what
i want in the 1st place..
much thanks.. hope more chime in...
more snow last nite.. sigh..LOL
and im a skiier.. :)

Everett, WA(Zone 8a)

>> just mulch with the bark and let it eventually become part of the soil. Won't it sort of self compost?

That's a great plan. In my situation, I have to get organic matter into my soil as fast as I can, the clay is so bad.

>> bark fines as potting soil amendment ...
>> makes potting cheaper and better.

I agree 110%

>> Actually- since bark resists rotting, why try to compost it?

Yeah, the only reason would be to reduce that temporary nitrogen theft if you bury and mix very much fine bark into the soil. Give bacteria a chance to take their first snack on the bark in a compost pile, not right where your root hairs are.

Hopefully, whatever bark components can be digested rapidly will go quickly, then NOT steal as much N from your roots.

I never used to worry about bark-nitrogen-deficit, just sawdust & wood chip deficit. But comments and reading convinced me there is probably SOME nitrogen theft by bark.

But you're right: in beds, it is best used as mulch (especially, in thick chunks). That's what I do with the big chunks I screen out of bags of mulch or nuggets: coarse top-dress.

Wood chips are also said to be good as top-dress mulch. I've read that, after 2-3 years of lying on top of the soil, wood chips have broken down enough that their nitrogen-hunger is reduced. Me, I would rather wait 3-4 ye4ars, but I don't have any wood chips to worry about, yet!

When I have left-over bark fibers, dust, and fine fines, I'll keep turning it under my raised beds to improve my AWFUL clay ... but now I'll remember to fertilize more frequently for a few months.

>> size matters

I'm sure you're right. And it matters even more in containers. I wouldn't argue with You and Al about "similar size grains" in pots. That must be the most open recipe, when most grains are around the same size, they create many same-size channels. When I add any (or too much) smaller stuff, it must tend to clog up those channels with a water-retaining phase.

Provo, UT(Zone 5a)

it is so cool to find similar minded enthusiasts about
soil making,"best" potting mix..
i have 1 local friend that is as nuts as i am about
gardening,earth friendly,and trying something new
..getting as much info on it..and then trying it..
oh to have all of u in my neck of the woods !!! :)

Charlotte, NC(Zone 7b)

I break-up small dead twigs that fall from our trees and use them in the garden's pathways. After awhile, the paths feel very "spongy". We garden on a slope, so the broken down twigs help with soil erosion, and hold moisture in the soil.

Larger, dead branches are kept in a pile in the corner of our lot. Over the years, they have broken down into wonderful brown-colored "soil". I think EasternTowhee birds nest in the pile, so I've never tried harvesting the soil. I've seen snakes and spiders in the pile - they are all welcome inhabitants.

Milton, NH

Hi tropicalnut777! Did you compost the bark? If so, what is the status? Six years ago we received a cord of wood that was so soggy wet we had to dry it. After drying I had about 4 wheelbarrows full of bark which I just threw on top of my 'nature' area as a mulch. I would say about 10% of the bark mulch remains. I also added some of the hardwood bark into my hot compost piles in chips, chunks, and even hand size pieces. I noticed after the pile heated up for its fullest duration, cooled and seasoned, the bark had broken down significantly but not totally.

Provo, UT(Zone 5a)

hi sarah..
i found a local source of composted bark..$25/cu. yrd
between potted plants,where my tropicals are planted out
in gardens..i can use 5 yrds easy..
i will have pine bark end of season from my big potted tropicals
so im thinking of composting them for next yr..
also from ricks postings/research..and my own.. i think with my
potted up tropicals (they are BIG pots) i will keep using pine bark fines
as primary potting mix..
then again when dumping out mix i'll just compost it and incorporate it
into my garden beds..

Milton, NH

cool. . .seems only natural it could be composted.

Everett, WA(Zone 8a)

It breaks down so slowly (at least confier b ark, that's rich in suberin ), that I would think only a little composting would be enough to make its nitrogen deficiet negligible.

I bet a lot of the expense goes into drying it back out before bagging!

Provo, UT(Zone 5a)

i agree rick..
i figure .why not use the spent yr old bark i use in potting
my outdoor plant beds..
i always kid the neighbours..if we ever have a flood in our area
..i'll be selling tickets..since my property is the high ground ..from all
my hauling in of,compost,mulch,soil,sand,my own made compost..
im sure alot of u out there have storys to tell of how much youve added
to your property over the yrs..

Everett, WA(Zone 8a)

I'm like a proud father when I fluff up a raised bed with lots of compost. Then 6 months later it subsides and my pride follows.

Will top-dressing with compost keep the soil from shrinking?

Provo, UT(Zone 5a)

lol..nope..rick..:) i think we whatever way we
express ourselves in gardening.. and theres a TON of ways..
we have a kinship with the life..with seasons..with if you want to
call it..a "spirituality"
why else do we talk to our plants, feel connected to the earth,
pride in what we do..and when we fail.. we just take it on the
chin..and figure out what we were doing wrong,to much..whatever..
and what a wonderful forum..davesgarden..and more so.. all of u
that helps us on the way..
wow.. where did that come from..LOL

Everett, WA(Zone 8a)

>> whatever way we express ourselves in gardening

Well said! Anywhere you have two gardeners, you have three or more different ways of doing things.

>> kinship with the life.. ..a "spirituality"

Amen. Where are you closer to God or the Goddess than in a garden?

Anne Arundel,, MD(Zone 7b)

"I'm like a proud father when I fluff up a raised bed with lots of compost. Then 6 months later it subsides and my pride follows."

haha been there!

close to a GOddess in the garden- you been stalking me ?? bigger haha

Even though some of my gardening time is ripping out bad things, I feel like I am nurturing when I garden. Or playing God maybe. I get to decide who goes where who lives and dies...and all my failures are blamed on weather or something else besides my skill or lack thereof.

Everett, WA(Zone 8a)

>> I get to decide who goes where who lives and dies

I used to flinch when I killed weeds, buty so many "wanted" plants have been smothered out that I hardened my heart. Now the only thing that keeps me from being a mass-weed-murderer is lac k of time and energy. But I kill as many as I can, and no longer feel gulity!

Well, I don't feel guilty about killing the invasive weeds. I know I'll never get them all. But a spindly weed with small blooms does make me feel a little guilty. I get over it, though!

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