Sustainable medium

[ewn4]

Hello All. I recently re-potted my first orchid in a commercially-bought bark mixture, but the materials did get me thinking... In general I've been trying to increase my level of environmental sustainability in pretty much every arena.

After lots of research into growing media, including water culture, semi-hydro, coconut-based varieties, etc...I'm left with one burning question. Why can't I just grow my phal using whatever shedding bark I find in my local park mixed with some stones from the yard, some larger sticks or pieces of mulch, and a couple leaves? Let's assume it's all sterilized.

Why the mix? I've spent hours trying to find someone who has done this, but the internet is full of those who seek the perfect highly-specialized media, not the most sustainable. So, can what I propose be done successfully?

[estación seca]

Originally Posted by ewn4

So, can what I propose be done successfully?

Probably. Could there really be only 3 or 4 kinds of trees whose processed bark can be sold in packages and that orchids will tolerate?

Recall some kinds of trees have bark with lots of tannins, which can affect roots negatively. And all natural products are colonized with lots of bacteria and fungi - though many fungi are good for plants.

Try it and report back.

[bil]

I pot phals in two inch chunks of pine bark. That's sustainable, as I assume it's the waste from the pine industry. (paper, pit props, whatever.)

I don't mix it with anything.

[Ray]

It's not just tannins; many plants' bark contains compounds that are there specifically to ward off parasites and competing species, rendering them toxic to orchids. Some brands of orchid bark are steamed to remove those, although that degrades it. Others are aged or composted to allow natural decomposition of those toxins.
The folks from Pacific Wide / Besgrow farm their sphagnum and the pines used for Orchiata. That sounds pretty sustainable to me.


Ray Barkalow
firstrays.com

[Optimist]

I don't see why not. In fact I saw a video about Andys orchids on You tube. He plants many of his sales orchids on plaques and sticks from the cuttings from tree trimming companies. I think he said most of his sticks are from manzanita trees.

Hickory is said to be great for orchids, if you can get it. I have been tempted to get a bag of hickory pieces for barbeque and use them. Hickory supports a fungii that lives in simbiosis with the ghost orchid. Not that it comes with the fungi on it already.

Hard woods that would not break down are what you need. To the idea of leaf litter I would say no, because it breaks down To quickly. I feel that lava (scoria) is most cost effective because it does not break down.

---------- Post added at 08:33 AM ---------- Previous post was at 07:19 AM ----------

Also, many of the bags of potting materials are for the sake of convienience. Many orchid growers formulate their own mixes. I've never understood the need for charcol for instance. It removes some toxins, but it is also very short lived. Why keep it in there?

[Fairorchids]

1. Many woods (& barks) are incompatible with orchids.

2. Few tree species grow bark, that is thick enough to be used for orchids.

3. Charcoal lasts far longer than bark, and is reported to extend the life of the mix (= longer than pure bark, or spaghnum/bark).

4. While a permanent medium (say lava rock, or Aliflor as used in SH methods) is fine for monopodial plants, it is not the solution for sympodial plants, which slowly grow out of the pot/basket. When you have to repot every 18-60 months, you have to look for other solutions.

Considering that the US building & paper industries use vast amounts of wood, there is a continuous supply of bark (even if some of it is not suitable for orchids). In some mills, the bark is burned for heating, in some it is not, so this is almost like a waste product being re-purposed.

You are of course free to experiment (just be aware that not all woods/barks are suitable). I know of one grower, who has several Vandas & Ascocendas in baskets, filled with wine bottle corks for the roots to hold onto.

[desertanimal]

This is what I like about LECA. It uses resources for materials and processing, but after the initial time, I can keep reusing it and reusing it and reusing it.

[Leafmite]

I use LECA and red lava rock as it doesn't need replaced. The first time I had to re-pot the orchids, I did buy bark and I thought...'What a waste!' as I threw away all the old bark. I didn't like how it decayed and held more water, either. Then there was the aspect of feeling as if I was just throwing away money. So, the next year, while buying some tomato plants, I saw the bags of red lava rock and thought....hmm. I tried it and it worked very well, even for Phals and Paphs. I used red lava rock for a long time and, recently, I have added LECA to the list of mediums.

If we think about it, most orchids grow on rocks or living trees, with terrestrial orchids living in the loose leaf litter of the forest floor (or in crevices filled with organic matter. Orchids that live in decaying matter in nature are considered terrestrial.). To me, bark makes little sense. Unless sterilized, it can possibly carry virus or other diseases/pests and it decays, thus requiring an unnatural disturbance of the roots. Removing the bark from the roots during a re-pot can end up with damaged roots, too, and can take a good deal of time. It just does not seem to make much sense to me to grow orchids in bark.

I have bought quite a few mounted orchids from Andy's. If the mounts ever deteriorate, the orchids will be going into red lava rock or LECA.

[Ray]

Be careful of assuming those inter materials will never need replacing. While they may not decompose, they do build up minerals and plant waste products over time, turning into toxic pellets, and no matter how much you flush, you'll never get it all out, especially if the degree of contamination is significant.

[Leafmite]

Nearly any medium can become toxic...even the soil in one's yard. I believe that taking good care of the medium is what makes the difference.
I've had some of my plants in the same pot with the same dirt for almost twenty-five years and some of the orchids have been in the same lava rock for ten. No problem, there. I am new with LECA, though, but I have been told that they are about the same with the need for flushing.
Much of the problem probably comes from over-fertilizing and not flushing well enough with distilled/rain water. Flushing has to be very thorough. I am very fortunate that the hard rains that come each summer do the work for me.