This moisture meter has a spike which you push into pots and tubs and immediately shows how much moisture there is at the bottom of the pot. I got it for Christmas and is a great boon. I now know that even if a tub looks dry at the top it may not necessarily need watering, and you can water plants before their leaves flop.
I like things that work and this is great, it was bought in Homebase, but I expect you can get it in Home Depot or Lowes.
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![Image](http://www.zyxwv.co.uk/pics3/mm.jpg)