I googled 'hotbed' to get a definition:
hotbed : noun
Having trawled through all of them, I set to and gathered up the following materials:
- a great big* pile of steaming fresh** horse manure - I reckon I had about 2 cubic metres.
- * you need a reasonable volume for this to work.
- ** it has to be fresh to generate heat.
- some faggots of tree prunings - suggested by some writers as a way of building up the structure if you'e a bit short of manure.
- as many barrowloads of beech leaves as I could be bothered to rake up - some accounts suggest adding leaves as a way to temper the fierce heat of the manure.
...so here is my step by step 'hotbed photo guide':
Build up the edges of each layer first then fill in the middle -
make sure it's all firmed down so that it doesn't sink unevenly.
Fill the frame with about 20cm depth of soil/compost mix.
I have a fancy glazed 'light' to go on top of the frame, but old window units would work just as well.
The heat should start to build up rapidly over the next few days - the books say that you should wait for the temperature to stabilise somewhere in the region of 21-23 Celsius before sowing seeds. This seems wildly ambitious at the moment, but who am I to doubt the wisdom of the ancients? I have stuck a thermometer in and will report on progress - I feel a chart coming on....