Rockwool cubes - and how to use them ?

**Dorsetman** · July 7th, 2011, 03:20 AM

I have never used rockwool successfully ; I don't like to look of it, and in Europe at least, it is illegal to put the used stuff into waste dumps without pre-treatment - so it is not used much, if at all, in commercial horticulture ( whereas a few years ago most all tomatoes and cucumbers etc were grown in it ) and I don't think that orchid growers use it the way they once did.

Buit I recently showed a magnificent Thunia ( see my Peterborough Show pics ) which I have discovered was grown in this stuff - rockwool cubes . I have not had a chance to discuss watering with the grower (yet) and my question is what is the watering regime in rockwool cubes ? Does one start by soaking, or just pour through ? And then water how often ? Or can you stand a plant in a saucer of water ?

It’s not what you put in the pot, it’s what happens afterwards, I think… and I have no experience of success in this stuff.

**kiwiorchids** · July 7th, 2011, 04:27 AM

I would not have a clue sorry, but i was curious as to what this stuff is, so i googled it. Apparently it is good for growing marijuana in.... and they use it hydroponically for tomatoes still etc...

**Cjcorner** · July 7th, 2011, 10:40 AM

I found some recently mixed in with regular potting stuff on a cattleya. It had rotted the roots all over the place. In my experience it is used mainly in the hydro stuff, as pointed out above. It holds too much water for regular potting it would seem to me. However, having said that...i'm sure there is someone somewhere who can use this successfully. lol Just not me...