Keeping your plants warm during the winter can sometimes feel like an impossible task. There are many greenhouse heating options, but one method stands above the others for those looking for a natural solution to their frosty greenhouse plants.
You can heat a greenhouse using only compost. This practice has been around since the 1940s, initially done with straw to heat greenhouses. The practice has evolved in recent years, and people have found that compost heating can effectively keep your space about 80°F (27°C) or more if maintained.
In our world’s current energy crisis, it’s imperative to seek green solutions that don’t tax our overburdened planet, and compost heating is a great option. Please read on to discover the mechanics of compost heating, the benefits, and how to heat your greenhouse only using comppost.
How Heating a Greenhouse With Compost Works
When you hear that you can heat your greenhouse only using compost, you might assume the process is more complex than it is or that you are simply using the compost to fuel some unique heater, but that is not the case.
Compost heating is just like it sounds. Compost naturally heats whatever space you place it in. So how exactly does it work?
Compost can create heat due to the microbial activity that begins to happen within the pile as these organisms break down the organic matter. As the microorganisms eat the compost materials, their exothermic reactions create heat.
How warm your pile gets is depended on a few factors, such as:
These factors work together to produce heat, and compost can significantly heat the space in an enclosed space, such as a greenhouse. However, you must use a wide variety of green and brown plant matter to get the best results.
Whether you own a glass or plastic greenhouse, this heating method is a great option to keep all the frost at bay.
Benefits of Heating a Greenhouse With Compost
So now that you know a little about how composting can be a heat source, let’s talk about a few of the benefits of this heating method.
Compost heating benefits:
- Using compost in a greenhouse enriches the compost. Not only will your compost be rich in nutrients for your plants, but it will also generally be free of weeds since it has had no contact with the outside world.
- Compost as a greenhouse heating source creates more carbon dioxide (CO2) for your plants. Plants quickly use their CO2 supply in their enclosed greenhouse, and having a constant source of new CO2 can help your plants thrive.
- Compost keeps your greenhouse warm. Hot composting leaves you with fantastic soil, but it will also help keep your plants toasty in the cold winter.
- Compost heating helps increase humidity. A good compost heater can help create more humidity in your greenhouse so long as the compost is sufficiently moist.
- Compost is cost-effective. Apart from the material required to construct your compost heater, this heating process is entirely free and has relatively low maintenance.
- Compost heating is a renewable and eco-friendly option. As a natural heating source, compost spares the world’s overburdened resources.
As you can see, there are a few fantastic benefits to this type of heating, and who doesn’t love a free heat source that also turns out great soil? So let’s learn a little about how much heat this excellent compost heater can produce.
How Much Heat Can a Compost Pile Produce?
So far, compost heating is probably sounding pretty good to you, but you might be wondering just how warm can your compost heater get. Will it be enough heat to protect your plants from frost in the winter?
At its center, a compost pile can produce 130-140°F (55-63°C). However, if you maintain your compost pile, your greenhouse will most likely remain about 80°F (27°C). How much heat your compost generates will be dependent on the size, quantity, and types of nutrients provided.
Compost heating is a great way to heat your greenhouse and has become increasingly popular next to propane heating in recent years due to its effectiveness and low maintenance cost.
It’s important to note that how much heat your compost produces will depend on size and nutrients. However, either way, you should notice a rapid increase in temperature in as little as one week after setting it up.
How Long Will a Compost Heater Last?
It’s truly amazing how warm a pile of organic matter can get with little to no effort on your part. So now that you understand just how much heat these organic heaters can produce, it’s time to talk about how long they can last.
A Compost heater will last about 18 months. Around the 16-18-month mark, the heat will begin to dwindle, and it will be time to replace it with new nutrient-dense compost. By replacing the compost, you can use the old compost for gardening and new material to keep your plants warm in the winter.
If you notice that the heat in your greenhouse is beginning to die off, it’s probably time to replace your compost and use the old pile as soil for your plants. By replacing the compost, you should notice new heat within a week of starting a new compost pile.
How To Make a Compost Heater for Your Greenhouse
Last but not least, it’s time to discuss how you can set up your compost heater for your greenhouse. The process is simple and will generally yield results within a week of construction.
You will need:
- Wood planks
- Staple gun
- Mesh wire
- Compostable materials like fruit, veggies, animal droppings, and other plant matter.
Your materials don’t need to be brand new; in fact, old wood from a free pallet you have lying around will work just fine. How much wood you need and the exact sizing will be dependent on how large or small you want your compost pile to be.
The design you want to aim for when constructing your compost pile is a coffee table without a top. It should slightly resemble that shape, though your pile may be longer or shorter depending on your needs.
How to make a compost heater:
- Create a rectangle-shaped structure. The composter should somewhat resemble a coffee table with no top. How large you make your compost heater is entirely up to you, how much heat you need, and the available space.
- Staple the chicken wire along the outside of the composter. This barrier will help ensure that the compost remains inside the structure and has adequate air to function correctly.
- Add in the compost mix. Your compost should consist of compostable food scraps, animal feces, and plenty of green and brown plant matter.
- Create a lid out of plants. Dry leaves or old lawn clipping make an excellent cap to lock all the moisture into your compost to achieve optimal heat.
- Water the compost pile. For your compost to do its job, it needs to remain moist. This moisture will also help to increase the humidity inside of your greenhouse.
- Wait. It can take about a week for all the microorganisms to get to work and for you to notice a significant temperature change. So be patient while waiting for your organic heater to mature.
As you can see, the compost creation process is relatively simple, and you can do it with materials you have lying around. Plus, it’s a pretty cost-effective way to heat your greenhouse during those cold winter months.
If you are a visual learner and want to see what an excellent functional compost heater looks like, check out Greg Pryor Homestead’s video passive heating with compost. He does a great job explaining how his composter has helped heat his greenhouse.
You certainly can heat a greenhouse using only compost, and it’s one of the most cost-effective and low-maintenance options out there. This type of heater is an excellent heat source, but it will also provide you with nutrient-rich compost for your plants all year.