How to heat your greenhouse in winter

How to heat your greenhouse in winter

Posted by Alix Francis on 5th Feb 2018

Getting through the winter months and protecting your tender plants from the harsh frosts is a challenge every gardener must take on. No one wants their plants to turn into a soggy mush.

Heating a greenhouse can become quite expensive depending on how you choose to heat it. There are methods you can use to help keep the costs to a minimum by making a few simple adjustments and improvements.

You can use materials to insulate your greenhouse such as; straw, cardboard & bubble wrap or you could invest in a SpaceSaver Greenhouse or buy a Paraffin Heater which are inexpensive to run.

Before investing in a heater, it is recommended to add insulation to your greenhouse, most greenhouses lose their heat through small gaps in the structure which let in draughts.

Insulating your Greenhouse

  • Repair structure - If you have any cracks or broken panels, patch these up before you start insulating the greenhouse.
  • Invest in a thermostat – Thermostats are a great way to gage when you need to apply heat to the greenhouse and these nifty gadgets can also help you save money and energy too. Investing in a thermostat that can activate heating when the temperature drops below a certain point. You can pick up a decent wireless one for around £16.
  • Paraffin Heaters – Heating systems can be expensive to run and if you don’t have a mains supply of electricity you’re snookered. An inexpensive way to heat your greenhouse up is by using a paraffin heater. Check out our range of award winning heaters here.
  • Create Double Glazing - Use bubble wrap to add layers around the greenhouse to insulate it, the only thing to be aware of is that every layer of bubble wrap applied will reduce the amount of light into the greenhouse by about 10% which will essentially impact the growth of your plants.
  • Use a thermometer – Having a good thermometer is essential when heating your greenhouse, most plants don’t like a tropical environment and the cold winters frost can kill off your plants too, so knowing when to heat your greenhouse is critical. We would recommend having a thermometer with maximum and minimum readings that you can check on daily.
  • Horticultural Fleeces – You can add a layer or two of horticultural fleeces on those extra cold nights. The fleece can produce several degrees worth of heat and protection without having to use your heater or thermostat. If you do use a fleece, remember to remove it in the day, you don’t want your plants to miss out on daylight.
  • Ventilation – Before you go cooking your plants, you must remember to ventilate your greenhouse as heating it increases humidity. Ventilating your greenhouse will also prevent the spread of diseases and maintain a healthy growing environment. Make sure you clear down condensation on sunny mornings and close the windows, etc before sunset so you can trap some of the suns warmth in the greenhouse.
  • Use a propagator – Instead of heating the whole greenhouse, you can raise seedlings in an electric propagator.

What to look out for

Damp, moulds and rots can be extremely damaging in winter, despite how carefully you water your plants. On sunny days ventilation is key as it will shed the extra moisture which is created.

Some of your crops need more light than others, if you’re using the bubble wrap method to layer around the greenhouse, make sure that your crops get the sufficient amount of light they need to survive.

Simple solution

The simplest solution to heat your greenhouse would be using a paraffin heater.

Depending on the demand for heat isn’t too high through the winter and the outside temperature doesn’t drop below -6c, the required greenhouse heating temperature is typically around +5c. Paraffin heaters are able to provide the suitable amount of heat required and will keep your greenhouse frost free.

If you do opt for a paraffin heater, costs for running it will be fairly low but adding a layer of bubble wrap will obviously help with insulation of the heat too.


Depending on what route you choose to go, there are plenty of options available on how to heat your greenhouse in winter.

Check out our options we have available;

Discount Code:

Use this code to receive 10% off; NGBP0210

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