GF, that is interesting! I'm glad your worms were happy and sorry to hear the heat didn't pan out. About how big would you say the hole was? Any idea what volume of manure went in? My underground cold frame doesn't have a massive amount of manure under it, but I'm hoping it will be somewhat heated with the combination of a decent amount of manure and the hugelkultur wood, about two feet below it plus whatever I put into the base of it before planting. It's pretty deep so I should be able to load it up with more manure.
I have one bed called the "Aspen Hotbed" because it has a lot of manure... over 10,000 pounds in the one bed...
http://woodforfood.blogspot.com/2014/03/aspen-hotbed.html. It grew very nicely last year and this spring I started constructing a mini greenhouse over it to capture some of the heat. Then I had a dust devil problem (
http://woodforfood.blogspot.com/2014/03/dust-devil-eats-greenhouse.html) and I reconsidered my design! This mini greenhouse was different than the one that got eaten by the dust devil, but not strong enough that I felt confident following through and putting the walls up (yet). Our place is really windy. It seems it's always something! I wonder for how long 10,000 pounds of manure/hay mixture will give off heat. I guess I need a soil thermometer with a really long probe...