I use very aged, screened steer manure in the garden and vegetable garden but not on my bulbs or alpines. The organic component of my bulb planting mixture is topsoil that I dig up in my woodland, preferably under alder trees (deciduous and nitrogen-fixing) and put through a fairly coarse sieve. I pick out any visible live insects, centipedes, etc. There are, obviously, microorganisms of many kinds in this humus (and seeds, but there are few introduced weeds in the woods), but I haven't noticed any mushrooms coming up in the pots or any rotting. I also use a soluble chemical fertilizer 4 times a year on the potted bulbs. This has been effective and seems safe. I repot the bulbs every other year into freshly mixed soil. One thing that I avoid is using any kind of bark with bulbs. The microorganisms that break down bark and wood chips also appear to attack the tunics of bulbs, and probably other tissues when they're dormant in summer. You can see the white filaments (mycelia) in the bark and also on the non-growing underground parts of plants. Bark is the main ingredient in commercial potting mixes in this region (Pacific Northwest), meaning that I can't just order a truckload of mixed soil and, every summer, have to mix some cubic meters by hand. I will now be told that lilies grow fine in bark mix, and they do. I think this is because (a) they don't have tunics, and (b) they are in growth in summer, when the bark-eating organisms are active, and do not attack the actively growing lilies. Most of my bulbs, however, are dormant in summer. I stopped using chicken manure in the garden because a couple of loads I bought had dead chickens in them, to the disgusting delight of my Malamutes. I've never used horse manure because of the well-known weed problem. Mushroom compost was the preferred amendment when I started the garden, but when we got more information about its drawbacks, I quickly stopped using it. Jane McGary Northwestern Oregon, USA