Wednesday, 10 March 2010

Weird Science

Meet Nobby:

He arrived today and, with his pal Max (see below), will let me know when I can get started on my sowing schedule.

This week I'm establishing what the greenhouse and soil temperature base levels are.

The first day greenhouse temperatures are a bit perplexing:

Min -2C
Max 45C ???

Song: More Questions Than Answers


  1. Those are some strange temperatures you are measuring in the greenhouse... Maybe the sun hit directly to the thermostat.

  2. I never have understood these min/max thermometers....whats the deal with it...surely the temperature is what it is????

  3. Mal I went to a veg growing talk last year and the chap gave advice for making a greenhouse thermometer as you won't get accurate readings from a standard thermometer placed in the greenhouse. Here's the notes I wrote at the time although have never tried this "Greenhouse thermometer – litre glass bottle covered in tin foil, polystyrene lid sealed with beeswax. Full with water – insert a cheap thermometer though lid so bulb is half way down the water – accurate temp reading." Hope this helps I expect the high temp is direct sunlight/heat giving you an abnormal high reading as opposed to what the actual temp is. Hope this helps......or may just confuse more?

  4. I know that weather stations shade thermometers from the sun, but plants and seedlings won't have the benefit of that, vrtlarica. I don't think the instrument is lying. But perhaps I should provide some shade on sunny days (?).

    Tanya, please don't tell me you would have me sit in the greenhouse or vist it at hourly intervals throughout the day and night!!!

    Dynamo, Now that I have Nobby I can make a similar device by planting him in a pot of soil! Is a 'standard' thermometer that much cheaper that the £5 you can buy a soil thermometer for? Appreciate the suggestion though.

  5. My greenhouse has been lovely and hot in the sun this week, glorious days! Just a shame like you its been -5 at night!

  6. It can quite easily reach those temps under glass, I have to give all the newbies a lecture on dehydration. The rule I was given is ventilate freely but close up the house by late afternoon. A bit of fleece over your seedlings will protect from a couple of degrees of frost, as does a greenhouse/propagator within a greenhouse.