Our soil temp 2" down is 33F.
Have a look at this - http://tomclothier.hort.net/page11.html
I measured mine on monday and here in south norfolk it's 3.6C. Thats 38.5F
I visited on of 'my' gardens today and I was planning to start some serious digging on their veg patch...but I couldn't get the fork or spade into the ground. Frozen solid! bbbrrr
Yes I noticed it's still winter too ;D that looks like a good site Tim,
Still winter??? we have a layer of snow now where I live - very pretty and as it's the first snow I have seen this winter, so I am happy ;D
mat
Cloched my carrot bed on Feb 26th and measured the temperature as above, 3.6C. I'd placed a min-max thermometer under the cloche and the temperature has got as high as 30C. Today I thought the ground should be ready, but thought I would check the soil temp. 4.4C, I guess I'll have to wait a little bit longer. I suppose to be fair the rest of the ground is frozen.
Don't be fooled by high thermometer readings. If you want to measure true air temperature then you need some sort of makeshift Stevenson screen (the white louvred boxes you see on weather stations) to shield the thermometer from direct sun.
I use a little white cardboard box with the open side facing away from the sun. I was getting 30degC in my mini-greenhouse, now I'm reading a much more believable 22degC.
Robin
In the day it's getting up to 25 in the greenhouse and the vents are opening, at night it's been down to -4 in there.
with what type of thermometres are you measuring your soil temps with and where do you get them from?
It's one I borrowed from work, with a probe. I beleive a cooking thermometer with a probe is more than good enough.
Whichever - wherever!
With regard to soil temperatures i use a rather less scientific approach.
bare some flesh.....sit on the soil......if you find it uncomfortably cold then so will the seeds :o :o
just make sure no one sees you ;D
>>>>>>>fainted.
Now dread to go up the lottie incase there are men all sat naked on the soil :o
Tim that is a very useful site you have put me onto there.... Thanks
he he flowersofshona, what a lovely sight that would be ::) tis also the method used by some lay-dees too :-[ but since I don't tread on my beds I don't sit on them either, just use a bare arm ;D
A reminder of why we are checking soil temp.
Seed Germination Temperatures
Soil Temperature the rate affects both the rate of germination and growth of the seedlings. The
higher the tempeature the greater the rate of water absorption, nutrient uptake, translocation of
hormones, and many other physiological processes. Too high or too low of a temperature can
prevent germination or greatly reduce the rate of seed germination. Some cool season crop seeds
such as lettuce may become dormant at temperatures of 30 ºC ( 87 ºF ) or higher. At low
temperatures, seed may actually germinate but due to slow growth may never emerge from the soil
The following is a list of seed germination temperatures The temperatures given are the optimum
range for germination.
Agerium (70 to 80 ºF or 21 to 27 ºC )
Annual Alyssum ( 70 ºF or 21 ºC )
Beans, Bush or String ( 60 to 80 ºF or 15 to 27 ºC )
Beans, Lima ( 65 to 80 ºF or 19 to 27 ºC )
Beet ( 50 to 60 ºF or 10 to 15 ºC )
Begonia ( 65 to 70 ºF or 19 to 21 ºC )
Broccoli ( 50 to 85 ºF or 10 to 30 ºC )
Cabbage ( 50 to 85 ºF or 10 to 30 ºC )
Carrot ( 50 to 85 ºF or 10 to 30 ºC )
Coleus ( 70 to 80 ºF or 21 to 27 º C )
Corn ( 65 to 85 ºF or 19 to 30 º C )
Cucumber ( 70 to 80 ºF or 21 to 27 ºC )
Eggplant ( 70 to 80 ºF or 21 to 27 ºF )
Lettuce ( 40 to 75 ºF or 4 to 24 ºC )
Impatiens ( 60 to 70 ºF or 15 to 21 ºC )
Marigold ( 70 to 75 ºF or 21 to 24 ºC )
Melons ( 70 to 80 ºF or 21 to 27 ºC )
Onion ( 50 to 85 ºF or 10 to 30 ºC )
Pansy ( 70 ºF or 21 ºC )
Parsley ( 50 to 85 ºF or 10 to 30 ºC )
Peas ( 40 to 75 ºF or 4 to 24 º )
Peppers ( 70 to 80 ºF or 21 to 27 ºF )
Radish ( 50 to 85 ºF or 10 to 30 ºC )
Salvia ( 70 ºF or 21 ºC )
Squash ( 70 to 85 ºF or 21 to 30 ºC )
Tomato ( 70 to 80 ºF or 21 to 27 ºF )
Verbena ( 70 ºF or 21 ºC )
Vinca ( 75 to 80 ºF or 24 to 27 ºC )
Zinnia ( 80 ºF or 27 ºC )
I must recheck my allotment contract to verify that this sitting method is allowable under our terms and conditions ... ;D
Lettuce is the interesting one, Mike?
Quote from: tim on March 07, 2006, 10:34:43
Lettuce is the interesting one, Mike?
Yes, but somehow I can't believe that if I sow lettuce outside at the moment it will grow. I'll continue starting it inside for the rest of this month at least.
Regards
Lettuce is indeed the interesting one.
Clever stuff, lettuce seed. It germinates at much lower temperatures than most veg, but not when it gets too hot
Fresh seed won't germinate unless it gets the right kind of light. Red light makes it germinate, darkness or light from the far infrared part of the spectrum stops it germinating. Older seed stops caring about the light, though and germinates anyway.
That's a really useful list MikeB, any chance of sticking it on the wiki?
Hi SS, O.K.
What's the general rule about light for germination? I read so much conflicting advice in books about covering with black plastic or putting on a bright windowsill.
Robin
Did anyone know that Metcheck (http://www.metcheck.com/V40/UK/FREE/trendmaker.asp) offer a soil temperature forecast for the next 180 hours. You can select different depths and it plots a neat little graph for you too. Remember to enter your postcode.
You can plot lots of other things on the same graph too, including soil moisture levels, and even solar energy in W/m2.
QuoteWhat's the general rule about light for germination? I read so much conflicting advice in books about covering with black plastic or putting on a bright windowsill.
Robin
Hmm Good point. I think some seeds like light and others dont. Hmmmm....
I think that makes sense. I started up a thread about brown plastic bottles as use for propergaters over plantpots and was at first belive that it would restrict to much light stopping the seed from growing. But! Since then I was thinking that it may aid germanation and may increase the germanation rate because it is restricting the light to a certain level. Enought for germanation and enought to allow the seedlings to grow on.
I feel an experiment comming on.
The_Snail
Is it OK to sow lettuce in cold greenhouse now?
I have got some of mine in, and they have now germinated grawrc.
I was frightened that I was cooking them earlier in the month because the sun raised the temperature in the greenhouse to 27c ::)
Rosemary