Dave: Rocks and stones tend to rise to the surface of most strata due to the constant settling and degradation of the medium. It is simple physics. Small stuff goes down (compacts) and large stuff goes up. Any dirt farmer knows this. Plants, on the other hand, are living motile organisms that respond to their environments. I am afraid that your rock idea would be, especially in frost or freezing prone climates, fairly predictable, whereas your bulbs may be doing something quite different. The plant stem concept is intriguing, however, especially the bit about the transference of motion from wind action. Never gave a lot of thought to that before in this particular context, but now that I do, it makes sense when one considers that most plants react to regular wind by making more and tougher roots and stronger stems. Vibrating a bulb that wants to remain stable (again, in a fluid medium, to paraphrase Jim Shields) may well encourage the bulb to craft its toughest roots and, also, drift downwards depending upon shifting soil densities. Any thoughts on this, anyone? Rand I.T.G.W. North >Hey, here's an idea! > Why don't some of us plant some well marked, bulb sized and shaped rocks >while we're planting various bulbs. In a year or two, we can check back to see >where the rocks are in the soil. Perhaps one could glue some wire or cord to >the bottoms of some to simulate non-contractile roots. Unless the rocks sprout >real roots, this should give us a good baseline of the movement of objects in >the soil, something to which to compare the bulbs' movement. > > Also, there is the as yet unmentioned effects of the plant stem itself, >during the growing season. The stem can have a considerable percentage of the >weight of the total plant, pressing downward on the bulb. Also, when the wind >blows, there is a rocking action produced at the bulb, at least to some degree. > >Just some thoughts > >Dave >7A- Tumwater, Washington, where we have now had our summer ... yesterday (sigh) > > >_______________________________________________ >pbs mailing list >pbs@lists.ibiblio.org >http://www.pacificbulbsociety.org/list.php