Temperatures are dropping meanwhile (especially at night) but I want to try cultivating certain suitable greens over the winter nonetheless. So, in order to keep the greenhouse frost-free, I ordered a greenhouse heater – this product in particular with about 300W of power. You can purchase it for around € 60,- if you’re willing to invest a little time surfing the net, and so far it works.

This model is designed for greenhouses of about 4m², but it seems to work sufficiently for my 6m² greenhouse as well. It burns normal lamp oil (the paraffin version, not the organic-stuff), which is cheap and easily obtainable everywhere, lasting for about 6 days with 4,5 l (more if you only use it intermittently).

At the moment, I only have it running at night, when there’s danger of frost and leave it off over the day.

Edit 29.11.2022:
While it absolutely does what it’s supposed to do (it keeps the greenhouse frost-free), I found that it’s a tedious fiddling to adjust the two wicks so they don’t either just self-extinguish and on the other hand don’t produce overly much soot. You absolutely must invest some time to find out an appripriate setting. Rating: 3/5 stars.

Edit 01.12.2022:
After several tries and thorough testing: Unfortunately, this contraption gobbles wicks, farts petroleum and nearly dies out by itself every morning. Sadly, I have to change my former rating to 0/5 stars. Not recommended, it’s a pity.

Example prices and links (de):