Dave There's a good questiion and it's partly a semantic matter, rather than a matter of culture of plants. What's being referred to here is actually a clay-based soil, a clayey loam ( in all likelihood). Using the cake metaphor is very good. and knifing leaves and compost into the clay is one way of doing it. . What this will do is break it up for better aeration You're going to improve your soil by adding a volume of compostable material (rough and only partially decomposed in an amount about equal to at least the volume of the clay--including bark and twigs). Start with about a good-sized shovelfull. Then add an amount of coarse builder's sand equal to the already improved (and worked volume) of material you started with. Clay is now about 1/4th the volume of the entire mess. Add in about a half pint of pelletized gypsum. Mix it all, water it, and it'll grow most plants very well. It should drain freely A large flower pot of it should drain in less than 5 minutes if filled to the brim and watered with a gallon of water. If it doesn't drain this fast, get coarser sand to add, and put in more of the coarse compostable material. Consider this a kind of baseline soil to work with. This may not work for everybody, but it works for me with the clayey loam I have here that turns to near concrete in the summer when the thermometer climbs into the 90s. I can grow most lilies in it, arisaemas, vegetables, local native plants, Asian arisaemas, rhododendrons and azaleas, lilies, irises, erythroniums,hymenocallis, hellebores, tree peonies and herbaceous types, etc. ----- Original Message ----- From: "Laura & Dave" <toadlily@olywa.net> To: "Pacific Bulb Society" <pbs@lists.ibiblio.org> Sent: Saturday, May 15, 2010 2:55 PM Subject: [pbs] A soil question > Hello all > Perhaps some of you can explain something regarding soils to me. I > was looking up culture for potted "Ipheion sellowianum" (yes, I know > that it may be called something else now), and I have once again run > across the phrase "a clay soil, rich in organic matter". When I think > of clay, it is the type found for making into pots, bowls, plates and > chalices. There is no organic matter, that I know of. When I've dug > around in the ground in Southern Ohio, at my in-laws' place, there seems > to be a layer of organic matter on the surface, in various stages of > decay as one descends into the soil, and then a fairly homogeneous layer > of clay, reaching down to bedrock. Is the organic matter spoken of in > the clay in a micro particle state in the clay? Or is the organic > matter at the molecular scale; that is, only organic molecules? > Does one duplicate this soil by putting compost into clay, and knifing > it in, kinda like making biscuits with shortening and flour? What > substitute soil type fools the plants into thinking that they are in > their ideal conditions? > I've come to the conclusion that soil is the key to understanding > plant growth; if you reverse the way one looks at plants, with the main > organism underground, and an attached solar collector, ventilation > system and reproductive organs all stuck up to wave around in the > weather, you see what I'm thinking. > However, the study of soil is a difficult subject, and I'd welcome any > help here that I can get!! > > Thanks > Dave Brastow, Tumwater Washington (7A) > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/