Does anybody use Rockwool as a growing Media?

If so, what do you think about it?

I think alot of people used to use it. I think it stays to wet over the long run. Sorry I do not have more info!

I've not used it either, but curious as to replies, also. Sorry I'm not more help!

I think it stays to wet over the long run


The reason I asked, is because about 2 months ago I was converted to Rockwool by a vendor. Anyway all but one of my Phals were potted in Rockwool as instructed. (along with some of my Paphs, Catts Cymbidiums and half my Phrags and Masdevalias.

I asked Paul Phillips about Rockwool and he said he had not used it but knows commercial institutions which did. He told me that I should not grow species (paphs) in rockwool as it stay too wet, well I had around 100 potted up already. He did say that the multifolrals seemed to benefit along with phargs.

When I got home, I checked the Phals which had stunning roots in bark...well 90% of all roots were mushy. The one which I had planted in a local moss had great roots. I repotted them in Sphagnum moss.

Yesterday I checked the rest of the orchids and this is what I found:

Paphs. Mushy Roots, only good roots were the ones that had were down in the gravel at the bottom.
Phrags. Nice roots, they seem to like it. Will keep checking
Cymbidiums. Excellent roots. But then they are outside where it is dryer.
Catts. Nice roots
Masdevallias. Terrible, has to removed about 90% of the roots.
Bulbos. They don't care they just grow ontop anyway.

I have a water rich setup, but the stuff in bark and stone do extreamly well. Luckily I only did some of my orchids, so I spent yesterday repotting about 280 orchids.

I think that in a dryer setup it could work well.

http://home.telkomsa.net/thomasriver/images/orchids/phalaenopsis_roots.jpg


For Sale: 20 kg Rockwool
60 kg recycled Rockwool...not really, will be used for the Cymbidiums

Gideon

I've been using a rockwool mix for the last 15 years. I use it for all my Paphs Phrags and most of my Bulbophyllums and Ive got excellent results.

Now it has not the same properties as bark so plants should be watered a different way and that may take some time to learn. Repotting plants from bark to rockwool need some precaution, be sure to remove all dead roots and all the bark pieces as well as they may encourage rot when in contact with the rockwool. Paul told you that he knew about nurseries using this. The Eric Young foundation use to use the greenmix (rockwool mix perlite rockwool lignite mix) but I've heard they switched over to bark, Mr Christiansen (Denmark) also uses this mix and he's the only manufacturer in Europe


Uri

I've been using a rockwool mix for the last 15 years. I use it for all my Paphs Phrags and most of my Bulbophyllums and Ive got excellent results

I don't doupt that many people have great success with Rockwool, as I said my Cattleyas and Cymbidiums just love the stuff.

It will just be too much of a change to alter my watering methods. I have read that it takes up to 4 months for the plant to develop a water tolerant root system. The problem is that I have already lost 2 Phals in 2 months, I just can't wait 4 months or more.


I see on the net that there are Rockwool cubes, this may be better than the granulated one we have here, or maybe if some stone or larger styrofoam chunks was added to the mix, so that more air could get to the roots.

Interesting discussion. Thanks!

I forgot

I use puzzolane which is volcanic rock as drainage in the bottom of the pot, before I used perlite as a drain but I encountered a lot of root rot problems.

For my rupicolous laelias I use a mix of 1/2 rockwool mix 1/2 volcanic rock and they seem to love it



Uri

I tried rockwool years ago....the stuff is creepy! At first, plants thrive in it...(I never tried it on paphs, just phals and pleurothallids)......they really seem to revive and look great. Then after a few months, the roots rot, and the surface gets covered by slimy algae and more fungus gnats than you have ever seen.....for moisture loving plants, I'll stick to NZ sphagnum....Take care, Eric

Eric

That's because jo didn't waited long enough, the so called slimy stuff turns into moss in a couple of weeks, prevents pots from drying out too quick

Uri

I personally never tried the stuff...but know a few people in our society who do. Apparently the most important thing is to get the right ratio of moisture repellent to moisture retentive rockwool mixed. I am thinking it was something like 60% repellent to 20% absorbant to 20% charcoal and perlite. I will eventually try it on a couple plants...just haven't wanted to spend the money on it when I have tons of my current media.

Jon

Uri- Actually, I did wait a long time...rather than turn over to moss, the algae eventually formed a hard crust over the rock wool....while this made it easier to remove, the plants roots had basically rotted by that point. I must add that years ago I didn't pay attention to pH with my fertilizers....I gather that rockwool in itself is somewhat acidic, and most fertilizers are acidic. I do not remember exactly what fertilizers I used in those days (it was at least 10 years ago)...probably DynaGro, but possibly a urea based fertilizer like Peter's ....I do know that I used to use bloom booster formula, which is definitely acidic...I now buffer my fertilizers (MSU formula) with Pro-tekt (only on paphs) and never use high P bloom boosters at all. take care, Eric

I am trying grow cubes( rockwool in cube shape) I am using it as an addative to my Phrags mix

Have tried rock wool (Grodon) and dont like it. There is water retentive rockswool and rockwool that rejects water. Have tried combinations of the two and other additives. I experiment a lot with this media and its not for me. The cubed type might be ok - it holds enough space between cubes to let in air and oxygen but I have no experience with it.

I've never tried it and never really seen it for that matter