The Supersoil change came some time ago and I've heard many growers repeat what Diana says here. All products are subject to change. Even a favorite plastic container can retain the same catalogue number but if they change the die to save material you have a thinner, less useful pot. For seed mixes, I use an organic base, often peat-based but there are other options. This component mostly provides moisture-retention and "fluffs up" the mix to prevent compaction of the roots. Perlite also improves aeration and prevents sogginess and compaction. Finally, I add sand (about 25%) and this is very helpful for several reasons: it allows easier re-wetting when mix is dry, it adds some weight/firmness and provides insulation when bulbs are dormant. Otherwise a peat-based or organic-based mix has a tendency to shrink into a ball when very dry (as in dormancy) and makes for more work overall. When seedling pots are on the dry side during repotting, a sandy mix makes separation of roots easier, and sand has an overall effect of extending the life of the mix. Sand is also inert and so never sours or degrades; most forms of it are also very cheap. Dylan Hannon Dylan Hannon Rare Bulbs On 24/11/2008, Telos Rare Bulbs <telosrarebulbs@suddenlink.net> wrote: > I have to comment on the recommendation for starting Tecophilaea seeds in > Supersoil. > > I used to use Supersoil, and it was a great product, steam sterilized and > mostly finely ground fir bark. Good stuff. Then the company was bought and > everything changed. It is no longer sterilized, and I won't say what it > looks like, since I don't want to get sued. It sure doesn't look like > ground fir bark. I don't use it any more and I would never recommend it, > even for mature bulbs. > > For seed starting I now use a seed starting mix from McConkey. It is very > finely ground peat moss with some vermiculite and perlite, plus a wetting > agent and some dolomite to adjust the pH. I add more perlite, since for > some species it is a bit too moisture retentive. It is very expensive, > especially with shipping. For small batches of seed you can make your own > seed starting mix by buying sphagnum peat moss and grinding it in a food > processor or blender. You can add a wetting agent, although it's not really > necessary for small pots, plus about 30% perlite for bulb seeds, and about a > quarter teaspoon of dolomitic lime for a quart of mix to adjust the pH. The > mix will be sterile, very important if you are sowing precious seed like > Tecophialaea. > > Diana > Telos Rare Bulbs > http://www.telosrarebulbs.com/ > http://www.thebulbmaven.typepad.com/ > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://www.pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >