Quite difficult to find out much about this - first, it seems hop manure is deficient in certain nutrients (though impossible to find out which) unless commercially produced, when it has added substances to correct that. Second, it appears to be good as a soil conditioner on heavy soils when applied as a mulch or dug in over winter. Seems to be a component of some home made compost mixes, but its not clear whether they're talking about commercially available hop manure or just spent material from producers of beer, etc. And that's all I can find out...

That's really helpful, Bamboo--thank you! I have really heavy clay so will find good use for it, and will also put some in my general compost heap hoping that that will provide the missing nutrients. I'm always a bit chary about composts and fertilizers since I managed to kill some plants with commercial chicken pellets!

Ah, yes, chicken pellets are very good, but should not be allowed to come into contact with plant roots unless you've had them in a bucket of water for at least 24 hours first - which then makes them mucky to use. Very good on unplanted ground, when you're first preparing an area.