Some days ago, I had taken the temperature in the greenhouse every 10 mins for several hours and shared the ups and downs with my readers. I have since taken the temperature again and again, not always noting it down, but being a bit concerned about it dropping below 19°C, when the ideal temperature for the olives and myrtle is between 22 and 25 °C.
Apparently, the fluctuating temperature didn’t bother the pomegranate seeds, as three have now germinated. However, I researched online for a rather cheap way to keep a constant temperature according to the preferred ones by the seeds. I found a heating cable by Romberg on Ebay for about 13 €. It is supposed to be laid out in the soil. However, as I have several pots in the mini greenhouse rather, that wasn’t possible. So I laid it out beneath, but with some distance between the cable and the greenhouse.
I had built a wooden frame for the greenhouse to stand on, because the window sill got rather warm and by standing on the wooden frame, it wouldn’t come into contact with the window sill.
They actually offer a heating mat for direct contact, but that was more expensive.
And this is what the cable actually looks like:
And now for the data. First a chart of the readings without the heating cable, using the normal central heating: