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Coconut husk chips vs Pine bark fines...

Posted by jsvand5 (My Page) on
Mon, Jun 23, 08 at 13:42

Would CHC's work better long term than pine bark fines? I have a few tropical fruit tree's that I am getting ready to pot up and was thinking of using 1/3 CHC, 1/3 turface, and 1/3 jungle growth potting mix. Seems like it would last longer with the CHC's rather that the fines to me. Can you think of any negatives to this or any suggested improvements? Also, what size CHC would be best?


Follow-Up Postings:

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RE: Coconut husk chips vs Pine bark fines...

I am sure Al will be along before too long, he has used CHCs and not been too impressed as I recall, however in general plants seem to grow poorly in them according to studies. Even peat moss seems to produce healthier plants.

Dunno if it is because they need to be fertilized differently or what, but I have looked at CHCs casually and pretty much written them off.


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RE: Coconut husk chips vs Pine bark fines...

Glad I read this before I placed my order. Do you know of an online company that sells Pine bark fines. I can't seem to find them locally.


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RE: Coconut husk chips vs Pine bark fines...

I am planting mango trees, and will be keeping them in the same container for a long time. Would the 1/3 bark fines, 1/3 turface, and 1/3 crushed granite be the best choice? Is the below pic the same as pine bark fines? I found this labeled as pine mulch and was wondering if it would work? It looks to be a good size, but I am not sure if it is thick enough (if the thickness even matters.)Any tips on places to look for the crushed granite or an acceptable substitute? I can't seem to find it anywhere.
Photobucket


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RE: Coconut husk chips vs Pine bark fines...

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Jun 23, 08 at 18:11

From what I've studied, there is little difference in the decomposition rates of CHCs vs pine/fir bark, and coir vs peat, so I wouldn't allow durability or longevity of the (soil) components sway my decision to use a coconut product or not.

After being pressed by a dear friend to try/evaluate CHC's, I performed a little experiment. Below, is a copy/paste job from a post I left somewhere, earlier this year. Though it starts out talking about coir, it ends with some commentary about CHCs.

Sphagnum peat and coir have nearly identical water retention curves. They both retain about 90-95% of their volume in water at saturation and release it over approximately the same curve until they both lock water up so tightly it's unavailable for plant uptake at about 30-33% saturation. Coir actually has less loft than sphagnum peat, and therefore, less aeration. Because of this propensity, coir should be used in mixes at lower %s than peat. Because of the tendency to compact, in the greenhouse industry, coir is primarily used in containers in sub-irrigation (bottom-watering) situations. Many sources produce coir that is high in soluble salts, so this can also be an issue.
Using coir or CHCs as the primary component of soils virtually eliminates lime or dolomitic lime as a Ca source because of their high pH (6+). Gypsum should be used as a Ca source, which helps correct coir and CHC's low S content. All coconut products are very high in K, very low in Ca, and have a potentially high Mn content, which can interfere with the uptake of Fe.

I haven't tested coir, but I have done some testing of CHCs (coconut husk chips) with some loose controls in place. After very thoroughly leaching and rinsing the chips several times, I made a 5:1:1 soil of pine bark:peat:perlite (which I know to be very productive) and a 5:1:1 mix of CHCs:peat:perlite. I planted 6 cuttings of snapdragon and 6 cuttings of Coleus (each from the same plant to help reduce genetic influences) in containers (same size/shape) of the different soils. I added dolomitic lime to the bark soil and gypsum to the CHC soil. After the cuttings struck, I eliminated all but the three strongest in each of the 4 containers. I watered each container with a weak solution of MG 12-4-8 with STEM added at each watering, and watered on an 'as needed basis', not on a schedule. The only difference in the fertilizer regimen was the fact that I included a small amount of MgSO4 (Epsom salts) to provide MG (the dolomitic lime in the bark soil contained the MG, while the gypsum (CaSO4) in the CHC soil did not. This difference was necessary because of the high pH of CHCs and coir.) for the CHC soil.

The results were startling. In both cases, the cuttings grown in the CHC's exhibited only about 1/2 the biomass at summer's end as the plants in the bark mix.

I just find it very difficult for a solid case to be made (aside from "It works for me") for the use of coir or CHC's. They're more expensive and more difficult to use effectively. The fact that some believe peat is in short supply (no where near true, btw) is easily offset by the effect of the carbon footprint of coir in its trek to the US from Sri Lanka or other exotic locales.

That's the view from here.

Al


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RE: Coconut husk chips vs Pine bark fines...

Al, would the pine bark in the above pic be ok to use? I am not quite clear on what is considered a "fine"?


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RE: Coconut husk chips vs Pine bark fines...

In your 1/3,1/3,1/3 mix what is the purpose of the crushed granite?


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fir bark

I think I have everything I need now. I think I am just going to order a bale of uncomposted fir bark online. I want this mix to pretty much last indefinitely so I assume the uncomposted fir bark will be better than what is pictured above?
I'm in a horse country in Ocala fl so the grani-grit was an easy find once I found out it could be bought at a feed store.


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RE: Coconut husk chips vs Pine bark fines...

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Jun 23, 08 at 22:07

The bark in the mix looks quite coarse for the 5:1:1 mix where it would be the primary component. It's closer to suitable in the gritty (equal parts) mix where it would be a component, secondary to other parts of roughly equal size, but still much larger than I would use myself. It also has a large portion of its volume in sapwood (>20%, by the look of it). The ideal bark for the 5:1:1 mix would be in size dust to 3/8, with the bulk of the particles in the 1/16-3/16 size range. For the gritty (equal parts) mix, the ideal bark would have little dust & the bulk of the particles should be in the 1/8 - 5/16 size range. I know that's being pretty picky, but as long as we're talking 'ideal' here .....

In the equal parts mix, the granite and Turface are used to control the water holding ability of the soil. Increase Turface & decrease granite = a more water-retentive soil. Decreasing Turface and increasing granite = a less water-retentive soil.

Al


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RE: Coconut husk chips vs Pine bark fines...

Al, would the pine bark in the above pic be ok to use? I am not quite clear on what is considered a "fine"?

Hard to say without a size reference in the pic. Think half the size of a dime or smaller for most purposes. The purpose of granite in a mix is drainage. Granite doesn't hold any water. Bark holds quite a bit, more as it starts to decompose. Turface also holds a lot of water. I will probably have to repot my new citrus trees that are in 1 part bark fines, 1 part Turface as the mix continues to hold water too long even though summer temps have arrived.


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RE: Coconut husk chips vs Pine bark fines...

Yea, I kind of figured that would not work. I'll just break down and order a bale of fine fir bark from an orchid supply company. When switching trees from the nursery pot to your 1/3,1/3,1/3 mix do you remove all of the nursery soil from the roots?


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RE: Coconut husk chips vs Pine bark fines...

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Jun 23, 08 at 23:29

You need to consider timing when you do a repot (as opposed to potting up). You can't just bare-root a plant in full leaf & expect it to react favorably. That treatment, for instance, would kill a high % of woody deciduous material. You don't mention where you live (important info), but it may be prudent to simply pot-up now and nurse your mangos through until late winter & repot then, before the main push in spring.

Al


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RE: Coconut husk chips vs Pine bark fines...

I am in FL so I may be better off waiting until winter. I think when the mango's arrive I will just pot them up with the mix I have been using (Jungle growth potting mix, the pine bark pictured above and perilite) and go with your mix in the winter. My other mango's and lychee's have been growing very well in the above mix. I am just looking for something a little more stable.


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