Time to turn on the lights and warmth.

This week the temperature has plummeted. All our Harvsters are showing a marked downward trend on the charts, which means it’s time to turn on the heating.

We initially trialled space heating, using a common greenhouse heater. This works to a point, but doesn’t get the inside of the Harvster as warm as we wanted. We’re working on improving the insulation and sealing out the draughts which should make a difference – but we’re also running heated seed trays which keep a smaller amount of soil toasty and warm. It’s easy to keep your seedlings at a fixed 18 degrees, say, using the thermostatic control feature of the control unit.

Here’s the data from one of our early test boxes, running the heating to maintain a nice steady temperature for germinating a tray of spinach and chard seeds.

We’re also running grow lights, to give the germinated seedlings a boost as the evenings draw in. We get lots of light here normally; we’re quite exposed and have a big sky, but by running the lights for a few hours in the morning and evening we’re hoping to get good, strong crops sooner than normal.

Which is just as well, since the garden is now starting to dry up; we had our last courgette today. We’re not going to starve though, there’s another Harvster out there which is packed with chard, spring onions, peppers, spinach and salad – we can’t eat through it fast enough!