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The Insider Secret on Heating Greenhouses

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do you need to learn about heating greenhouses? Gardening in cold climates through winter? Then learn the insider secrets on heating greenhouses to understand your options. Greenhouses typically are extremely inefficient building structures.

Like any business that can’t afford extended downtime due to an unforeseen power outage. So no matter what option you decide, don’t forget to ventilate your greenhouse to control humidity.

You can heat a little greenhouse easily with an electrical tube heater with a programmable timer. This affords you control and an automatic solution to heating your greenhouse.

Table of Contents

Heating greenhouses by preserving heat

To continue to keep temperatures relatively steady in your greenhouse. You will need some form of heater and some way to regulate the heat. Maintaining the necessary temperature in the greenhouse or glasshouse is vital for the plants you want to grow.

Ceramic Tube Greenhouse Heater
Heater 2ft Tube with Built-in Thermostat

On the flip side, it’s advantageous when heating greenhouses that you attain various temperatures throughout the greenhouse. You can take advantage of directed infrared heat to create multiple heating zones. This will provide the perfect atmosphere for unique species of plants.

If you’ve got a greenhouse, you’re fortunate enough to have the ability to stretch your growing season by a month or two. A lean-to greenhouse is a kind of attached greenhouse structure that’s an extension of a single portion of the wall of your residence.

Greenhouses can be created of glass or crystal clear plastic. They can be as large or small as you would like. But heating greenhouses with a  ceramic heater can be a perfect way. Because that comes with a programmable timer. You won’t have to be worried about whether you turned it off.

infared Heater
Wall Mounted Electric Infrared Heater

A little greenhouse in the backyard may be enough. Although in some instances, larger, more complex greenhouses may be required. Many people are investing in larger structures such as high tunnels/polytunnels.


Because these give a lot more undercover growing space for your buck. but are harder to heat and keep frost-free. Check out the video below, which shows some alternative heating.

How To Heat A Greenhouse And Polytunnel

Different ways to heat

There are various ways in which people heat greenhouses. These range from electrical heaters where access to the power supply is available. For most people. Heating a greenhouse is a little more difficult due to its location of where it is situated.

Some may have them on an allotment. (community garden broken into growing plots for rent). These greenhouses cannot get power attached to them. Furthermore, owners and manufacturers have come up with some very inventive ideas. We will talk about a few of these below.

gas powered heater

Gas Power

A gas-powered heater is a great way to heat a greenhouse. They are relatively cheap and can be purchased in various output forms. This allows the gardener to choose the desired size. To suit the dimensions of their greenhouse.

They are fantastic at controlling the output with thermostatic controls. This allows you to dial in the desired temperature. Gas can be purchased at the local home depot store and is relatively inexpensive. So this means it is an easy alternative.

Further down the scale are fuel-style heaters. A lot of gardeners from the older generations use these. These are products such as paraffin heaters. These did a great job and stayed lit all night long. However, paraffin is now becoming more expensive by the day. It is still a great resource to heat a smaller greenhouse.

gas heater
parafin heater

Hot water systems

Some folks came up with hot water systems heated by a log or coal fire. The pipework was run around the greenhouse, and this water was moved by convection. This circulates a fluid without the necessity of a mechanical pump.

A hot water jacket is placed around the fire, and the water is circulated through the greenhouse. This heats the greenhouse with radiation. This system’s downfalls are that you must be at the greenhouse the last thing at night. And first thing in the morning. If it goes out, you could lose your plants.

mass heater
old shed with log burner

DIY Methods

Over the years, gardeners have found various DIY methods to heat smaller spaces. These won’t heat an entire greenhouse but are more of a growing room within the greenhouse. Because to be able to do this, you would need to fashion a small insulated area using bubble wrap. It’s easier to heat just this small space within the greenhouse.

The 100-hour candle was created by Simplify Gardening a few years ago. It is a DIY method for heating these small spaces. Another method that is quicker to refuel once built is the DIY Copper Coil Alcohol burner.

So both of these are fantastic ways in which to heat smaller spaces within the greenhouse. It is possible to heat an entire greenhouse using this method, but multiple candles would be required.

How to Make a 100 Hr Candle
Copper Coil Heater

Tips to Consider

Whatever heating source you choose, there are a few things to remember.

  1. The heat source needs to remain constant
  2. It needs to be easy to use at short notice
  3. Heat is lost very quickly from a greenhouse. Please don’t turn it off unless temps are high.
  4. Ventilation is very important to remove any fumes that have built up.
  5. Be safe do not place anything near the heater. For DIY versions, consider placing it into a steel tin or box.


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