Tim, There is a summer suite of weeds in SoCal (*Chamaesyce maculata, Portulaca oleracea*, most grasses) that are long day plants. A corresponding (and apparently larger) number of weeds are winter obligates. Their respective cues are not dissimilar to those that distinguish summer and winter bulbs. I don't know a lot about water but enough to know that it is a complex subject. The potential harm or benefit of "hard water" depends on what is in it. If it is mainly calcium and magnesium, e.g., it is much less likely to be of concern to bulb growers. In fact these minerals are needed so that such water may be better than water stripped of its suspended solids. If the solids are heavy in sodium it is bad news for most plants. Fortunately, the contortions that growers of other groups like orchids, ferns, etc., go through to obtain pure water are not a concern for most of us. An important consideration is the pH of the medium itself. An acidic mix can offset alkaline water. When testing water it is advisable to test the "hose end" product as well as the leachate-- the water that comes out of the drainage holes. Dylan On 26 October 2012 18:12, Tim Harvey <zigur@hotmail.com> wrote: > > Joe, > > Can you provide more details - controls, types and numbers of seed used? > What do you think is the mechanism whereby hard water prevents absorption > by seeds? > I water all my seeds with hard, alkaline city tap water and have excellent > results from many genera and families, not just bulbs. > > Like many bulbs, California weeds are also adapted to its climate, and > many don't germinate in summer even if watered. > > T > > > > From: plantnut@cox.net > > I have experimented growing seeds with tap water and distilled and/or > rain water. The difference can be amazing. It is much more difficult for > seeds to absorb tap water because of its 'hardness'. > I believe this is > the reason that I can water my gardens with tap water all summer with few > weeds germinating. With the first rains of fall weeds are germinating > everywhere!! Joe, Oceanside, CA > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >