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Using Wood-Fiber Soil For Cannabis

Emeraldo

Well-Known Member
I'm always checking out the soil pH on the back of the packages in the garden store, just to see what is available. I'm an outdoor grower in soil in pots. I don't use the store-bought stuff uncritically, and if I can find a good one, it might make up 50% of the supersoil that ultimately goes in the bottom of the pot, after making many amendments.

Anyway, I found a new soil product the other day. New to me, cuz I hadn't seen it before. It's a wood-fiber product and the reason I bought it was because the label says it has a pH of 5.8, which makes it a good starting point, pH-wise, for my current grow which includes Arjan's Haze #1 (GHS recommends a soil pH of 5.7).

Labeled "berry soil," this is a 50/50 blend of wood fiber and composted bark. So I mixed up my soil using 15 L of "berry soil" per 30-L tub of soil -- so the wood-fiber product makes up roughly 50% of my final soil mix. To which I added 2 L peat moss, making my soil base mix a wood-fiber/peat blend. Then I added the usual stuff (5 L of used soil from my last grow, 5 L composted horse/cow manure, 2 L perlite, 1 L worm castings and 1 cup lime; and further amendments, in cups and teaspoon amounts, include bat guano, blood meal, cottonseed meal, horn meal, pelletized chicken manure, fish bone meal, rock dust, cali-mag, etc.). My question to you all is about the wood-fiber base mix.

Has anyone used wood-fiber soils? Did you have good results? Any issues? I just wondered about the use of wood fiber for cannabis. I did a little checking and saw that peat moss is said to increase porosity, airflow, water-flow and -retention of wood fiber substrates, see Substrates on trial: wood fiber in the spotlight The article concludes that up to 20% peat moss in a wood-fiber substrate actually integrates the soil beneficially.

I'd be interested to hear any experiences or any thoughts on wood-fiber as a soil component.
 
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Blew Hiller

Grow Journal of the Month: June 2019
I had access to large amount of chipped wood (finger size) that I would use for mulching and such...after sitting for a few years it would get some interesting fungal growth, but only the bark in trees has any nutrients...so there is a lot of filler in that soil. You add enough amendments to counterbalance it so it really comes down to the cost.

Do you make your own compost?
 

Emeraldo

Well-Known Member
Hi Blew and thanks for responding. No, I didn't compost the manure myself.

But it makes sense that the wood fiber part is just that, a filler. Creates a medium with good air and water flow. The composted bark is the nutrition in this product out of the bag. In the berry soil, the ingredients are chopped pretty fine, the biggest piece of wood is about a half-inch splinter, the bark is already composted into a soil-like state. I'm attaching a photo of my soil tubs, the texture is not "woody" at all. Probably not as rich as FoxFarm OF, but I can't get that here, so hopefully the amendments I made will work.
 

bobrown14

Grow Journal of the Month: Dec 2017
Probably call it "berry" soil due to the lower pH. Blueberries like acidic soil.

To acidify soil you can add a very small amount of elemental Sulfur. I use it a little bit around our rhododendrons (wild version) and azaleas. They are in ground not a container.

Composted wood.... prolly better to burn that stuff and use the ashes.
Home made pot-ash.... its good stuff and will be slightly acidic as well.
 

Emeraldo

Well-Known Member
Thanks bob for that. I doubt I will burn it for "pot ash", but I'll keep that in mind. :)

The blueberries in the photo just happened to be in the greenhouse where I'm letting the new cannabis soil mix settle in after watering.

My question was if you have ever used a wood-fiber based soil in growing cannabis. I've not used it before, but I don't see why this one, with pH 5.8, wouldn't work as a base.
 

bobrown14

Grow Journal of the Month: Dec 2017
We make our own vermi-compost. I grow in soil organically so the humus portion is the most important part of my soil mix.

I prefer to use home made so I know whats going into it.

I see all sorts of stuff they call soil or compost at the box stores here and well I wood pass on all but the Canadian Peat moss. I buy the Premier brand.
 

Emeraldo

Well-Known Member
I wood not have gotten the berry soil if it weren't clear what it is. It is 50/50 wood-fiber/composted bark. Sounds natural enough. I just wondered if there wood be something about wood that would make it unsuitable for cannabis. Wood it, or woodn't it?
 

bobrown14

Grow Journal of the Month: Dec 2017
Forrest floor filled with decomposing wood. Works for trees.

Problems are if its NOT composted. Say using wood chips in your soil mix wood be a bad idea. They take a long time to break down. Several years actually.

People make the mistake to mulch flower beds with wood chips only to watch all the flowers die. It's sooo sad when I see that.
 

Emeraldo

Well-Known Member
Yeah, I think this stuff is going to make an excellent soil base. I double-checked the package and there are no nutritional additives, no NPK, no nothing except wood fiber and composted bark. I added peat moss, which somehow is said to bond with the wood fiber in a way that creates an optimal soil regarding aeration, drainage, etc. But the fact that this is not your processed "soil" containing chemical nutrients is a relief and gives control over what I do add.
 

Emeraldo

Well-Known Member
That sounds GREAT!

I think composted tree bark is pretty good stuff. I've watched a few piles of it the forestry people pile up. There's a ton of activity and the soil is black all around each pile.

Compost ! woot
Thanks Bob. All in all, am pretty optimistic this soil is going to work out well. And years of re-use will make it better! Heck, I'll even throw in some old dead roots to spice it up!

Probably the composed tree bark is what makes this "berry soil" work initially. Just wood chips by itself would not make a soil. This is pretty finely chopped or ground wood fiber plus the bark compost.

Innovative, because you actually have to add your amendments and nutrients, it doesn't come with much of anything in it, just what the bark compost might have. The manufacturer is not adding anything else. I like this.

Will post more after my grow is complete.
 

Emeraldo

Well-Known Member
That's very similar to Canadian Sphagnum Peat Moss.

I use a fair amount of Calcium in my amendment mix that is 1/3 Peat Moss.

Both long, medium and short term Ca and lots of rock dust.
Please explain. Why do you add Ca specifically to peat moss? What is their interaction?

Adding a substantial amount of Calcium carbonate to peat moss would of course raise the pH (Ca is about 9.0 as far as I know). Is that what you're thinking?

Also, what kind of Ca is short- and long-term?
 
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bobrown14

Grow Journal of the Month: Dec 2017
Please explain. Why do you add Ca specifically to peat moss? What is their interaction?

Adding a substantial amount of Calcium carbonate to peat moss would of course raise the pH (Ca is about 9.0 as far as I know). Is that what you're thinking?

Also, what kind of Ca is short- and long-term?

I don't add in Calcium Carbonate per se.

I add in Gypsum Dust, Oyster shell flour and crustacean meal in equal amounts.

That gives the soil short term, medium and long term Ca. The micro-oganisms have to work with those amendments to make a soluble form for the plants to uptake along with water.

Why some of those I listed are long term Ca release.

Short to medium = Gypsum
Medium to long = crustacean meal
Oyster shell flour = short, medium and long term

There's a balance/ratio that needs to be had with the Mg.


The Ca:Mg ratio is very important in container gardening. Go for 7:1 Ca to Mg.

Plants will uptake the Ca WAY faster than the Mg.
 

Emeraldo

Well-Known Member
I don't add in Calcium Carbonate per se.

I add in Gypsum Dust, Oyster shell flour and crustacean meal in equal amounts.

That gives the soil short term, medium and long term Ca. The micro-oganisms have to work with those amendments to make a soluble form for the plants to uptake along with water.

Why some of those I listed are long term Ca release.

Short to medium = Gypsum
Medium to long = crustacean meal
Oyster shell flour = short, medium and long term

There's a balance/ratio that needs to be had with the Mg.


The Ca:Mg ratio is very important in container gardening. Go for 7:1 Ca to Mg.

Plants will uptake the Ca WAY faster than the Mg.
Ok, Bob, but -- pleez pardon my persistence -- what does this have to do with peat moss? You said you add Ca to peat moss, and now I see you are also talking about container soil and micro-organisms that help with uptake. Is it that peat moss is so lacking in Ca that you need to add it?
 
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