Anyone do Compost Heating?

[saboten]

Does anyone here who lives in colder climes do compost heat beds? -or- Saboten's hare-brained idea

So, I know that some people use manure hot beds to supplement their greenhouse's heat. I guess a lot of people do it judging by reading around online, but I don't know anyone personally who does. I would like to know if it is supergross or just kind of gross.

That leads to my crazy idea: I have a good old rabbit, and as anyone who has kept a rabbit knows, they produce a tremendous amount of little manure pellets. These are fairly inoffensive by themselves (rabbit urine is ANOTHER THING COMPLETELY and could probably be used as biological warfare) and we have always just put them in the corner of the yard. But I thought to myself, Why not put all those pellets to use? What if I made a smallish cold frame and let it get a little heated by a bed of rabbit manure and stuff during the winter?

Is this a crazy idea? Do people even use rabbit manure in this way? Are there dangers? I have yet to research it in-depth, but I figured I could open a topic for hot composting, since there didn't seem to be one yet (unless I missed it).

[DaveW]

Unusual here in modern times where electric or gas greenhouse heating is common in the UK. However in Victorian times I believe they did use that method to grow melons etc in our unfavourable climate. But in those days it was only the aristocracy that had greenhouses and their gardeners were cheap labour to maintain such compost beds. Also with larger gardens and more horses more compost and horse and other animal manure was available. Whether you will have a large enough mass of rabbit droppings I do not know. The problem I see is you getting enough manure, since horses droppings are much larger than rabbits!

Anyway found these for you:-

http://www.the-gardeners-calendar.co.uk ... efault.asp

https://www.permaculture.co.uk/articles ... and-manure

https://alaskamastergardener.community. ... eenhouses/

https://permies.com/t/32439/Simple-comp ... cold-frame

Another thought is do you have a riding stable near you? Don't know about Riyadh, but some stables sell horse manure cheaply in the UK, but some are glad for you to take it away to get rid of it and a bag plus your rabbit droppings may be a better starter to get it heating up? Regarding hay in the mixture. I have noticed when I pile my grass cuttings up from the lawn within a day or two the centre of the heap gets quite hot, so these mixed in with your manure may act as an accelerator?

[Crassulacean]

I do. I have a 6x8 harbor freight greenhouse. I put 1/2 inch XPS insulation panels on the north wall and have 80 watts of Christmas lights up. I am in zone 6a.

I also have a 40 ish gallon drum compost tumbler and 6-10 inches of decaying logs and mulch on the floor. There isn't a smell at all once you have a healthy ecosystem in the tumbler but this is household waste not manure. The decaying biomass does help significantly I think compared to the results I've heard of others getting with (mostly unheated) greenhouses.

I think it keeps us in zone 9a right now. I have many citrus trees and only the eureka lemon was damaged on the coldest night (6 F) outside before I added Christmas lights and insulation. Our banana tree had to be moved inside. All of our echevevrias are fine as is opuntia engelmanii, trichocereus peruvianus, echinopsis oxygona and a few agave species. Pilosocereus polygonus and aloe vera had some tip die back over a few weeks. Pereskiopsis, and some kalanchoe like things died back to the soil pretty quickly.

Its not gotten as cold as it will but I am still improving the insulation and will be adding another 150 watts of Christmas lights so I am hopefully I will be able to keep it above freezing at all times when I am finished. There is no way I could do that and still only spend 50 bucks over the entire winter in supplemental heating.

[saboten]

Thanks for the input, folks. Thanks for chiming in, too, Crassulacean; it's nice to see that it can actually work. I am not sure if I have the time/means to get one started right now, but I'll be thinking about it. I suppose it wouldn't take much to just start a composting drum on its own, though.

[DaveW]

Problem with most Christmas lights now is they are LED's (at least in the UK) and don't give off much heat like the old incandescent bulbs.