Since so many growers here like to start their seeds indoors, by necessity or preference, it may be worthwhile for them to set up a small low rpm fan to drift over the seedbed or seed pots 24 hrs (or most of the time). This would help reduce excess moisture retention, which seems to be the main issue as far as algae, etc. It would also improve the general air exchange and circulation in any enclosed space at a low cost. Normally I sow in small pots (3" or 4" square) in a mix of sharp sand, rather fine perlite and rather fine peat, in descending order but not precise proportions. I find it beneficial-- very important actually-- to top off the pot (when completely finished) at or very close to the actual rim. I add an obligate layer of fine granite that is roughly no. 10 grade (used in roofing here). With a few exceptions these pots all get free or limited rain exposure and limited direct morning sun and this suits a wide range of species quite nicely. The algae and wetness are, I think, mainly, a function of too much watering and (mostly indoor) conditions that do not allow proper drying. Dylan Hannon Los Angeles On 1 February 2012 15:57, Tim Chapman <tim@gingerwoodnursery.com> wrote: > > After a discussion here about a month ago ( where Physan 20 was mentioned) > I ordered some. I've used on trays with lachenalia and hippeastrum > seedlings. Initial I sprayed test areas but have now covered all of the > algae covered areas. It had no negative effect on even the youngest > Lachenalia seedlings ( the Hippeastrum hybrids were older and much larger). > I didn't do a drench just used a spray bottle to soak the algae. I did > mist the seedlings slightly just to get the chemical off of the leaves, but > not enough to wash it off the top layer of the trays. I've had algae > issues in the greenhouse every year due in part to our humidity and part to > moisture retaining soil mixes. Even the mostly coarse sand seed mix I've > made will get algae at some point. > > It seems to work quickly without negative effects. > > Tim Chapman > > > > Do you have any experiences with seedlings ?? > > > > Roland > > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > -- Where there is much desire to learn, there of necessity will be much arguing, much writing, many opinions; for opinion in good men is but knowledge in the making. — John Milton, *Areopagitica: A speech for the liberty of unlicensed printing to the Parliament of England*, 1644