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How to Heat a Greenhouse With Compost

la serre des cierges image by jean claude braun from

Hot composting, also known as aerobic composting is the process of making compost very rapidly by turning the compost. This differs from cold compost, in which a compost pile slowly breaks down over a long period of time. During the process of hot composting the gardener mixes the compost to make the microbes in the pile more active. As the active microbes decompose the compost, their activity heats up the pile. A well-managed compost pile will generate up to 160 degrees of heat. If you locate your hot compost pile in a greenhouse, you can use this heat to warm the air in the greenhouse.

Dig a trench in your greenhouse that is at least three cubic feet.

Gather materials for your compost pile consisting of organic green compost ingredients and organic brown compost materials. Organic green compost items include grass clippings, kitchen scraps, clover, peat moss and manure. Organic browns include dead leaves, straw, hay, sawdust and wood chips.

Chop all your compost ingredients into inch-long pieces. You can render down kitchen scraps with a pair of kitchen shears or a food processor. You can use a lawn mower to cut down grass, dead leaves, straw or hay.

Layer the trench with alternating layers of organic green material and organic brown material.

Water the compost pile until it is the consistency of a wrung-out sponge.

Throw a handful of finished compost into the pile to activate the compost process.

Check your compost pile daily with an oven thermometer. Plunge the probe of the thermometer into the center of the pile to check the temperature. Stir the pile with a pitchfork to raise the temperature anytime it drops below 120 degrees.

Sift through your pile with a sieve when the compost pile is mostly reduced to fine dirt. Pick out any unfinished, large pieces of compost and return them to the pile to include in your next batch of compost. You will be able to use the fine loam, which is finished compost in your greenhouse.


As compost nears the finished product, it will produce less heat. You can dig multiple trenches and start multiple batches at different times for a constant supply of heat.

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