Autumn has arrived and the temperatures are dropping fast. Soon, garden plants will start to die off for the winter, and it many gardeners will retreat indoors until spring arrives.

It’s a different matter in the greenhouse – and with the right gas and electric greenhouse heaters, you can continue to grow throughout the autumn and winter months, whilst protecting your tender plants from damaging cold, snow and frost.

In this guide, we look at the different types of greenhouse heater, and show you what to look for in the right system for your garden.

Benefits of a greenhouse heater

Whether you go electric or gas, a greenhouse heater will deliver real benefits in the garden, enabling you to:

  • Protect tender plants – preventing hard frost from damaging your favourite plants
  • Increase growing variety – enabling you to grow a wider range of exotic plants
  • Grow for longer – extending the growing season for longer
  • Start growing earlier – get a head-start on next year’s growing

Batten down the hatches

Before you think about investing in a greenhouse heater, it’s sensible to take all the steps you can to insulate and protect your greenhouse. There’s little point heating a greenhouse if it has lots of draughts, cracks or gaps – most of the heat will escape, and you will end up wasting a lot of fuel and energy, pushing up the cost.

Replacing broken panels, checking seals and ensuring that all your doors and windows close flush is a great starting point.

Things to consider

Before purchasing a greenhouse heater, you will want to consider the following:

  • What are your goals – do you want to protect plants, or raise the temperature sufficiently to allow for year round growing?
  • Output – heaters are available in a huge range of different sizes, and it’s essential to choose one that’s right for the space
  • Budget – what can you afford, and how much do you want to spend?
  • Fuel type – do you want to go gas or electric? (see below for in-depth advice and guidance)
  • Controls – what kind of thermostat/timer/temperature control does it have?

When sizing your greenhouse heater, you’ll need to measure the area, before thinking about the maximum temperature you need to achieve. Check with the product guidelines, or contact a member of our team for additional support.

Gas or electric

Both gas and electric heaters have their benefits and downsides:


  • Safe – with no fumes, combustion or open flames to worry about
  • Convenient – as long as you have a power supply nearby!
  • Even heating – many come with built-in fans for better heat distribution
  • Controllable – many are fitted with thermostatic controls for easy use

On the downside, they do tend to be more expensive to buy, and do require access to a mains power supply.


  • Flexible – no need for mains power
  • Powerful – with a range of outputs suitable for greenhouses of all sizes
  • Co2 emissions – beneficial to growing plants
  • Easy – relocate them whenever you need to

As a minus, you will need to think about ventilation, to ensure that the dangerous fumes can escape. They also tend to be less efficient than electric heaters, which can increase running costs.

Greenhouse Heaters at Keen Gardener

You’ll find a fantastic range of gas, electric and paraffin greenhouse heaters at Keen Gardener, from trusted brands including Bio Green, Hotbox and Lifestyle. With so much choice, and models to suit greenhouses of all sizes, there’s something for every garden.

In fact, we stock everything needed to keep your garden growing and your plants protected until spring! Check out our fantastic selection of greenhouses, greenhouse heaters and frost protection, all available at unbeatable prices and guaranteed by our Lowest Price Promise.