Greenhouse Heating: How To Heat Your Greenhouse For Less

The challenges of maintaining impeccable produce during colder months might appear formidable. But the truth is that achieving a flourishing all-season garden is well within your grasp. This is particularly true when cultivating within your very own garden greenhouse.

As winter’s chill sets in, your gardening journey need not come to a halt. For one, this nurturing structure transforms it into an exciting opportunity to give it a go.

Read on, and unlock the ways to maintain the ideal greenhouse temperature year-round. The best part? You can extend your growing season without breaking the bank!

Greenhouses Explained

BillyOh 4000 Lincoln Wooden Clear Wall Greenhouse with Roof Vent
BillyOh 4000 Lincoln Wooden Clear Wall Greenhouse with Roof Vent

Greenhouses boast versatility across all seasons and weather conditions. These structures create a nurturing haven for plants. On top of providing the ideal growth environment, they shield them from frost damage. The materials for these sanctuaries are diverse as the benefits they bestow:

Uncover a treasure trove of advantages that accompany greenhouse ownership. From extended growing seasons to efficient seed germination, the rewards are endless. It stands as a paragon of practicality in the realm of gardening solutions.

Moreover, they are naturally warmed throughout the day by the sun. But here’s a problem: retaining heat at night poses a challenge. Fear not, for an array of cost-effective methods exist. With these techniques, you can preserve that warmth without resorting to central heating.

In the following section, we will show you how to achieve it.

Heating Your Greenhouse For Less this Winter

There are so many great options if you’re looking to heat your greenhouse. For example, adding a greenhouse electric heater can provide endless benefits. But some of the below methods can still be done in a greenhouse without electricity.

But why is heating so important in the first place? A heating system ensures your plants are getting the right amount of heat. Perfect for year-round growth, you can expect successful plant production in return. This approach especially works wonders during the winter months.

And the cherry on top? It doesn’t cost much while making sure there are no harmful chemicals released within. Below are some of the do-it-yourself tricks you can follow to heat your plant sanctuary:

1. Thermal water storage tanks

Domestic rainwater conservation

(Image Credit: Geograph UK)

Water stands as an economical and accessible solar heat accumulator. So here’s a trick: position water reservoirs and rocks within your hobby greenhouse. This combination captures and locks in heat. Thus, placing them around your unit can generate heat back into the structure.

To achieve this, fill black or dark-coloured gallon drums and place them along the end of the wall. Buckets also work great as an alternative. This is a great way to preserve solar energy and ensure an electric greenhouse heater isn’t needed.

Top tip: Collect rainwater in a barrel through water pipes.

2. Below the frost line

Constructing a partially submerged greenhouse below the frost line can be a game-changer. This approach capitalises on the abundant thermal mass present underground. Notably, the subterranean part boasts a consistently higher temperature. Thus, furnishing an advantageous foundation for temperature regulation.

The frost line delineates the threshold at which soil moisture commences freezing. In the context of the UK, this pivotal point rests at a depth of 0.45 metres below the surface. By situating your greenhouse within this realm, a wellspring of heat emerges.

The soil, thus harnessed, evolves into a potent source of natural heat. This ensures your wooden green house thrives even in the coldest of nights.

3. Save the heat

Mini greenhouse situated in a small garden

(Image Credit: Plantly)

Loss of heat can cost you both money and energy in the long run. Keeping in the heat from a greenhouses 6×6 doesn’t have to be a difficult task. Simply preserve the heat already in the building. This means making sure the walls are covered carefully to reduce heat loss. Or consider the following methods below:

  • Insulation: To achieve this, you use bubble wrap insulation. Go around your walls with a layer of bubble wrap. This is a cheap and effective way to keep the heat in. Use horticultural bubble wrap for this. It’s cheaper, longer-lasting and can even withstand UV light.
  • Wrapping plants with bubble wrap: Do so to provide them with extra warmth. This can also prevent your pots from cracking. If bubble wrap isn’t available to you, plastic sheeting is another great choice. Make sure to clean lean the windows before filling the structure with this material. Otherwise, this could reduce the ability of light to get inside.
  • Double-glazing: While initially requiring a higher investment, it proves its worth over time. The dual layers of glass create an effective thermal barrier. They trap heat inside while preventing external colds from permeating. Overall, it minimises heat loss, enhances temperature regulation and reduces heating costs.

4. Invest in a thermometer or a thermostat

Garden thermometer

(Image Credit: Wallpaper Flare)

Having a thermometer can ensure you have accurate temperature readings. Even better, you’ll never have to guess!

A thermostat is also a great investment and an effective method if you’re looking to save money and energy. Having one enables you to set the heater. You can even schedule it if the temperature drops below a certain point.

5. The plastic bottle cheat

Passive solar plastic bottles are a great cost-effective alternative to solar heating. And although similar to the tanks, this option means you can reuse recycled bottles. You’re also able to place these along walls, saving you much-needed floor space. So save some of those cluttering the shed, paint them black, and fill them with water.

Darker colours help absorb more heat. Meaning at night, the heat will be retained and released automatically. It’s best to place these all around your walk in greenhouse for amazing results.

Note: Results can vary depending on your plants and produce. Each plant has a different need of its own, so looking into each specifically is vital.


Results can vary depending on your plants and produce. Each plant has a different need of its own, so looking into each specifically is vital. But nonetheless, these methods are cost-effective and efficient ways to heat your greenhouse.

Thinking of investing in a greenhouse for sale near me soon? Garden Buildings Direct offer a range of units in different sizes and styles to suit every need. Check out this list of best greenhouses UK for reference! Might as well give this apex potting shed a look as a complementary feature.

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The best way to do this is to recycle. Save the heat you already have or use plastic bottles. Both methods can be found above.

It can be helpful to heat your greenhouse in winter. Some plants will need some warmth to survive. Plant growth rates will slow down in winter though.

No. Your greenhouse will always be at least 5 degrees warmer than the temperature outside. This is without even heating your greenhouse.

Yes. Depending on what you grow, you may need to heat your greenhouse. You can grow in an unheated greenhouse still, but check up on which plants need heat first.

It's beneficial for your greenhouse to get at least 6 hours of sun a day. Especially in winter. Positioning your greenhouse is an important first step towards heat efficiency.

Yes. Water is best for this. Water placed in a black drum or plastic bottles will continue heating your greenhouse, even at night.