>By definition, clay balls do not improve drainage. As they create a >permanent water table at the >bottom of pots they are widely used in >balconies and places where frequent watering of potted plants is not >possible. GREAT when you go on vacations! >From: "Alberto Castillo" <ezeizabotgard@hotmail.com> >Reply-To: Pacific Bulb Society <pbs@lists.ibiblio.org> >To: pbs@lists.ibiblio.org >Subject: Re: [pbs] Hippeastrum seeds >Date: Wed, 20 Jul 2005 18:30:14 +0000 This definition is interesting and I can not verify the postulated consequences. My experiences with and without drainage layer consisting of clay balls revealed a significant difference in the necessary maximum time interval for water administering: 4 days WITH drainage and 6 days without using my 50 cm boxes demonstrated in my previous images. Thus I can not confirm the water table theory. I did not talk about seramis, volume related water binding capacity = 25% here, but about porous balls with an outer skin similar to these 8 mm balls which are used for hydroculture. I roughly estimate their surfacial water "up"take to be only between 5 and 10 vol% - while the water binding capacity of coco peat substrate is 40% or better (I evaluated this myself) which makes my differential observations above (6 vs. 4 days) plausible. The hippeastrum seedlings growing in coco peat "with" this drainage layer below simply grow much better (faster) which is plausible, too, because they get more air from below! My observations over the years indicate that Hippeastrum roots need a lot of oxygen! And therefore I strongly recommend and continue to recommend a THICK drainage layer of these 2-4 mm balls! Hans-Werner