Semi-hydro and (lack of?) healthy microbial/fungal activity

[xscd]

Hello all--

I recently ordered some of the improved PrimeAgra (both coarse and fine) "puffed clay" leca and have placed a few plants (paphiopedilums, African violets and a sundew (Drosera capensis)) into semi-hydro conditions and culture.

One of the things that worries me about the semi-hydroponic technique is the inorganic, inert media and the lack of (or very diminished presence of) microbial/fungal activity within the medium compared to more traditional potting media such as fir bark, sphagnum moss, coconut husks, etc.

One of the plants I transplanted into s/h was a paph with more than two dozen mature growths. It had been very healthy in its previous medium of a mixture of about 4 parts fir bark, 1 part sphagnum peat and 1 part regular (not coarse) perlite. I usually observe and smell the medium, just like I do for compost and garden soil, to judge whether there is a healthy mix of microbial activity going on, and the previous potting medium seemed to be a healthy environment (judging by the plant's growth). This new, almost sterile semi-hydroponic medium is a bit strange and difficult to accept for me as a gardener, perhaps not so difficult for the plants.

But I live with a retired University professor whose field of expertise was and is microbiology. He says that there is a lot of important research, especially recent research, about the interactions between plants and the fungal activities in the soil or medium in which they grow. According to him, plants can take up and use through their roots some amino acids, for example, that are produced by fungi and that are not ordinarily present in chemical fertilizers such as those used in hydroponic culture.

Part of me, the "organic gardener" part, wants to put my plants in healthy, microbially "infested" soil or medium somewhat like what they would be adapted to in nature. Another part of me is fascinated by the idea of an inert, inorganic planting medium that can be used over and over, will not rot or break down, and provides the necessary anchoring and moisture for the roots, and minimizing the destructive microbial and other problems that can occur in nature (although at the apparent expense of the constructive benefits of many microorganisms). So I'm torn between tradition and new ideas--

[Ray]

I have been growing plants in s/h culture for over ten years (including some that have not been repotted in over 5) and have never seen any deficiencies that could be associated with a lack of microbial action. Here's a few random thoughts that are rolling off my mind as I sit typing:

I have read about the need for fungal attack in order for orchid seeds to germinate in nature, and the need for such chemicals in germination and replate media is well-established, but have seen no references to their importance in the rest of their growth cycle. Not that I doubt it, though.

In nature, the majority of orchids are not sitting with their roots submerged in a medium, but are more-often rambling on the surface of trees' bark. There is nothing to say that such microbes might not stil exist and play a roll, but it has to be reduced compared to terrestrials, even in the cases of plants that collect detritus.

Just because the medium is initially inert doesn't mean it cannot support such growth. Over time, there will be the accumulation of "crud" in the pores, and as the microbes of which you speak probably are carried over by the plant, they should surely become established in the moist, airy medium.

So basically, I view it as a "non-issue".

[xscd]

Thank you Ray for your reply. It makes sense.

I had also read about the possible need for fungal activity around orchid spores, and I have often wondered if the clear, sugary droplets produced by many of my plants (usually on the flowering stems, for example) serves a purpose in nature by being washed by rain down to the root zone where the sugar might encourage fungal growth that would then encourage the germination of the soon-to-follow orchid spores.

At any rate, I am fascinated by the semi-hydro technique. The thought occurred to me recently that it might be more a matter of the grower adapting to the technique rather than the plants adapting to the medium or technique. As a grower for 12 years or so (and a gardener for many more), it is just hard for me to psychologically accept and get comfortable with the idea of placing plants' roots into basically sterile, inert, pH neutral clay "rice crispies."

However, I am fascinated with the technique and seem to have a green thumb with most plants, orchids and carnivorous plants included, so I am fairly confident in my ability to adapt and become comfortable to the new media and technique. To tell you the truth, although it is early in my own use of semi-hydro and the improved PrimeAgra (thank you so much in contributing to that process), the plants I have already placed in it, both young and mature, are surprising me by taking to the media and showing less transplant shock than I anticipated based on past experience with traditional media and repotting.

Thank you so much Ray for your many helpful and informative posts and responses regarding the subject of semi-hydroponic media and technique, which can seem strange to one who has only recently stumbled upon it.


Steve / xscd

[Tindomul]

Hi Steve, and welcome to Orchid Board.
I was wondering if,
well I would assume that most symbiotic fungi that live with orchids live directly on the roots, and in this way would get transported from old growing pot, to new growing pot.
I also assumed that with all the pores in LECA and and all the fertilizers we use, the fungi would have a home and food to live, and therefore continue to be present.
Ray,
I wonder how hard it would be to test for the presence of beneficial fungi etc.... in those very old cultures of yours.
Steve, I never thought of trying to grow african violets in S/H. I think its worth a try. What have been your results so far?

[Ross]

Originally Posted by xscd

At any rate, I am fascinated by the semi-hydro technique. The thought occurred to me recently that it might be more a matter of the grower adapting to the technique rather than the plants adapting to the medium or technique. As a grower for 12 years or so (and a gardener for many more), it is just hard for me to psychologically accept and get comfortable with the idea of placing plants' roots into basically sterile, inert, pH neutral clay "rice crispies."

Steve / xscd

Steve, what about true hydroponics? Many (if not most) plants seem to adjust to growing in constantly moving fertilizer solutions. That might be a stretch for certain terrestial orchids such as Calypso, etc., but many garden crops do just fine.

[bwester]

It is my opinion that the "new and improved" prime-agra is complete CRAP. Every slipper I put in it rotted and died a horrible death. Never had a single problem with the old stuff.

[Ray]

Sorry that the new stuff doesn't work for you, but there's more to success or failure than just the medium. This is the kind of results I am seeing:

The 2-growth division was moved from a 3" pot of organic-based medium into the "new" PrimeAgra about 14 months ago as part of my experimentation, and it has been fed with the GreenCare MSU fertilizer at every watering since. I actually snapped off a 5th inflorescence about a month ago.

PS: If you have a complaint Blake, at least have the decency to make it directly, and not as an off-topic snipe.

[Tindomul]

Jesus Christ! Ray! Thats gorgeous! I like golden colors on Slippers.

[xscd]

I'm new to PrimeAgra (and any leca) and new to semi-hydro concepts and techniques. I've read both positive and negative comments and experiences regarding the media and technique. I'm going to try it because I'm intrigued with the idea, and although I am very naive about it, I still think that getting used to semi-hydro may be more a matter of the adaptation of the grower, not necessarily the plant. A person has to get used to and comfortable with new ways of doing things before it starts to work well.

[cb977]

Ray, that's just stunning!
We all thank you for your constant supply of information on s/h and growing in general.