Cynthia’s Rabbit Warmed Greenhouse

I copied this from a newsletter I get. Thought you GH folks may find it interesting!

Cynthia’s Rabbit Warmed Greenhouse

Cynthia’s greenhouse is located in North Central Idaho, in a mountainous
region that is probably a USDA class 3b or 4a for hardiness. Normally, the
last frost occurs in early to mid June while the first frost usually occurs
in early September. This is a region with a very short growing season.
Summer temperatures rarely exceed 80˚. Winter temperatures typically
reach -10 to -30˚ F in January.

In spite of this, using this greenhouse, Cynthia is able to grow fresh
produce most of the year. There is no heating in the greenhouse other than
the rabbits and the composting activity that goes on under the rabbit
cages. Using this greenhouse, she is able to begin planting things like
tomatoes, etc. in February or March. The greenhouse is located to provide
full exposure to the sun from the southeast and south. To the west, there
is a hill and trees which shade the evening sun somewhat.

With this greenhouse, it is possible to get 9-10 months of production on
about 500 square feet of growing space. Normally, in this area, the
growing season will only last 2-3 months. As an example, when visited in
December, she was still growing kale in the beds.

Cynthia’s greenhouse is constructed as follows:

Overall dimensions: 14 ft. wide by 40 ft. long. Peak roof with wall
height of 8 ft. Roughly a 5-12 pitch on roof.

Construction materials: Rough cut 2x lumber for framing. East, South and
West walls and roof are formed using corrugated plastic sheeting. The
North wall is solid.

Rabbit hutches: total of 16 hutches. Two rows of eight each in the center
of the greenhouse. Hutches are 2 ft. by 4 ft. by 18-24 inches high.
Hutches are elevated approx. 2 ft off the ground and have screen bottoms,
allowing the droppings to fall through to the ground beneath. Droppings
from the rabbits are allowed to compost under the hutches. She then adds
this composted material to the grow beds in the greenhouse.

Grow beds: there are several grow beds in the greenhouse. One long wall
faces south. On this wall, there are three sets of grow beds, each roughly
18-24 inches wide, that run the length of the wall. One of these grow beds
rests on the ground. The second is elevated approx. 3 ft. above the first,
with the third elevated approx. 3 ft. above that one.

Another large grow bed is located approx. 2 ft. above the rabbit hutches.
It is 4 ft. wide by approx. 32 ft. long.

A fourth bed is located along the north wall, elevated about 6 ft. off the
ground. Like the ones on the south wall, it is approx. 18-24 inches wide
and 40 ft. long. There is a shelf below this grow bed for tools and
general work and storage space below that.

The framing for the roof extends over the center grow bed and provides
supports for climbing plants (such as beans, tomatoes, melons, etc.).
Fluorescent light fixtures are located over each grow bed and could be
potentially used for grow lights, although this is not done by Cynthia.

Ventilation: the only ventilation in the building are two man-doors in the
ends. She is able to keep the heat down in the summer simply by opening
these doors.

Composting: Cynthia allows the rabbit droppings to compost under the
cages. Media from the grow beds was originally sawdust, some sand, and the
composted rabbit droppings. She originally ordered in 1 lb. of red wiggler
worms to assist in the composting. She uses the composted material (and
worms) for all her grow beds. Very little additional fertilizer is used at
this point.

This is great. Were there pictures?

Nope, sorry.

Very interesting read, are these rabbits,raised for this particular reason,just heating the greenhouse,or is she marketing these rabbits as well?
I've been montoring the heat in my greenhouse,what effect the flourescent lighting has,I noticed a 3* temperature drop within the first 30 minutes after the lights shut off everynite,then maintains the same degree until very early morning,where it drops a couple more before the sun comes up.
Was wondering if anybody had notice that in theirs as well.
Mine shut off at 9 pm everynite,trying to stimulate mid summertime.

I'm going to try to find out more about the rabbit use, and hopefully photos as soon as I have time...

Thanks,this is truely interesting read.

I have tracked down a man who was on the visit, and he's given me a name & email of a woman who took photo's that day.I've written to her, and hope to hear back.

Fantastic,hope she answers you...

That's neat, wonder what the temperature stays at in the greenhouse with the rabbits, and Can you imagine the smell?

While I was trying to find some links to photos for the story above, I did a google search on rabbit-warmed greenhouses. There were a ton of threads and apparently this concept has been around for a long time.

I'd have to give up an awful lot of space, and would the rabbits burn up in the summer time LOL, I wouldn't mind trying this, but i'd be affraid I couldn't go to the greenhouse because of the smell. Wonder how many rabbits one would have to have . her greenhouse was n't too much bigger than mine, This is worth dong some research on for sure.

kathy

If she is composting the manure with other materials the smell might not be all that bad.
These are probably not pet rabbits,but eating rabbits....which are quite tasty,compared to the wild rabbits we ate as kids,not as tasty as fried squirrel,but not bad....and if you could add a horse,or cow.for a little larger and warmer fresh manure,who knows how warm you can bring the greenhouse too...

My friend Dan grew up on a farm. He says that a cow in your basement will keep your house warm enough that your pipes will not freeze if you lose power in the winter. I don't know how you get the cow up and down the stairs, but he lived on a remote Indian reservation in Washington as a boy, so it might be true.

Great story! Wish my greenhouse was big enough to do this, the electric heater about runs us out in February trying to germinate seed!

I remember reading Eric Sloan's stories about the early settlers in PA who kept all their livestock in the basement level, which heated all their personal living quarters.

Hmmmmm...Kathy....that is an interesting question...would the rabbits get too hot in the summer? I know that too much heat will kill a rabbit. Wonder if you could vent it enough to keep them cool? I used to take cold water bottles out to my rabbits in the summer...just so they could lay against them to keep cool.

that's a neat idea marcy, I don't think i'll be doing the rabbit thing in the greenhouse, I don't have any extra room for plants much less rabbits. I know my greenhouse was no hotter than 90 this summer, or I should say fall. that's with the fan going too. but that wasn't the middle of the summer, we didn't have it up untill september.

kathy

actuall, rabbit leavings have very little odor compared to other types of manure.

Just thinking futures ahead,some day,just maybe,will be heating our greenhouses with solar microwaves...

Oh, I surely hope not! I refuse to even have one in my home...

Well I think microwaves are used in cell phones, radios, and televisions now, who knows what else,there not telling the public.