I’d love to be able to determine soil temperature of my container citrus trees, but it’s impossible to buy a soil thermometer here. However, a friend of mine from Russia agreed to look for it on eBay.
Could you tell me what technical characteristics should I ask him to take into account?

(meat thermometers are also unavailable)

Any assistance is greatly appreciated.

Here have one.

http://www.allegro.pl/item983349635_niezawodny_termometr_glebowy_100_skuteczny.html

If they won’t send to you write to me.

Imenoq, I can't thank you enough.

I have this one:
http://www.plantes-et-jardins.com/catalogue/catalogue4.asp?id_variations=6597

It measures temperature, light, moisture and pH for 27€ !

Very useful
Sylvain..