>Good information to know. I assume (uh oh) that includes both beneficial and pathogenetic mycorrhiza? I don’t know. But I think you can see how difficult it would be to calculate a safe amount of phosphorus for pot-grown bulbs. I would think the simplest course of action would be to omit it altogether. Bob Nold Denver, Colorado, USA _______________________________________________ pbs mailing list pbs@lists.ibiblio.org http://pacificbulbsociety.org/list.php http://pacificbulbsociety.org/pbswiki/