I'm still pretty inexperienced, but for containers I've been having better luck judging by weight than anything else. I'd be interested in hearing opinions on this, and other methods of checking moisture.

I am pretty inexperienced on the gardening side too.

Am always looking for easy fool proof things to help.

Lifting numerous 15gallon pots is what i am trying to avoid :) 5gal and under not so bad.

d

It would be nice if they worked. At least they never have for me. Electronics here too. Your guess that each soil is different could be the reason.
The idea of weight might be good. My doctor tells me to weigh myself each day to judge my water retention.
Each container siting on its own scale with daily reading could be a very interesting experiment.
KennyP

col_sprg_maters Thank you so much for the insight. As a scientist myself I do not know why I didn't realize this with my probe. Sometimes you get so focused on the problem that you can't see what is obvious in front of you. I was doing a comparison with the finger test and the probe. When the soil felt just a little damp with my finger, the probe said the soil was more than sufficiently wet. I couldn't understand the difference. I have decided to go back to the tried and true method of just sticking my finger into the soil and getting a little dirty.

Got a bee in my bonnet and decided to run an experiment or 2 with moisture meters.

Here Goes:

Meter 1 is new stock meter,

Meter 2 is my modified meter- desensitized electronically and the big long element has black plastic electrical tape on all but the bottom inch of it.

Pot A is my version of a 3-1-1 bark/Sta-green/perlite -about a pound

Pot A starts pretty dry, reads barely a whimper on either meter, maybe a 0.5 to 1. I add water till it runs out the bottom. twice. stir, wait, re-meter. With a finger it feels like it should after being watered well.

Of course the two meters read different, but here are the important parts-
1. with the stock meter-- the deeper I push the meter, the wetter the soil number (3-5) reads; but not on the modified meter (~3). This is fairly fast soil, just watered.

2. on both meters, the more I compress this soil, the higher the meter reads. Max on the stock meter now goes to ~7, on the modified to ~5.

Now to Pot B;

Pot B is straight Lowes Sta Green out of the bag - about a pound In a large empty plastic yogurt container- says 2 lb size, about 3/4 full of mix.

The Sta-Green is moist out of the bag, but this is not a "fast" mix. I stir it thoroughly in the pot then pack it a little. Since I now know the modified meter is more accurate as depth changes, I concentrate on it. It reads a pretty consistent 4 throughout the pot. With a finger it feels like I would not add water unless next watering would be a long time away.

The only thing I do is add 3/4 dry weight oz of Espoma dry gardening lime, mix it well in the pot.
Now the meter goes to reading of a full 6 throughout the pot. hmm. pack the soil down pretty hard and it goes to a 7. No water was added. Some might say that's a lot of lime, but, I wanted to know quickly, so I did not go a 1/4 oz at a time.

These "back of the envelope" experiments are not designed for accuracy; they were run with about 60 seconds preparation and designed to tell me something quickly about a theory. It told me:

*The first thing is run experiments on a meter if you are thinking about trusting it.

*Next - tape off the long element for all but the top 1", use waterproof plastic tape- this helps ignore the effects of depth.

*The addition of certain garden additives can affect a moisture meter reading without the moisture changing.

*The packing density of the soil also effects the meter reading, with the same actual moisture level.

*No need to modify the electronics unless you have a need for a different scale or calibration.

*Compare your meter reading with the dowel/finger test to make the readings meaningful to you.

*IF you are not adding anything to your soil or changing the soil density, the meter readings can be useful on a given plant's soil over time.

*Between plants with the same mix and no items added at different times, the meter can also be useful; -i.e. a visitor caring for your plants for two weeks, adding nothing but water.

Anyway run your own tests, Draw your own conclusions, See what you come up with if you want to trust a meter. Me, I will be finding what dowel material I like best.

d

How about this 4-Pin Digital Wood Moisture Meter one for you? It seems for wood... here are the details:

# Weight : Approx 150g (battery included)
# Size: 126mm x 70mm x 29mm
# Professional and applied moisture measure instrument
# Large digital LCD display
# Range: 5% to 40%
# Resolution: +/- 1%
# High resolution and fast response
# Date hole and can hold value
# Symbol and unit display can read the value convenience
# Batteries: 9V battery
# 4-Pin version only leaves 4 small holes
# Accuracy: +/- 1%

Here is a link that might be useful: Digital Moisture Wood Firewood Damp Meter Tester 4-Pin

*IF you are not adding anything to your soil or changing the soil density, the meter readings can be useful on a given plant's soil over time.

IME the density changes slightly even with a light arid mix due to root development, weather and breakdown of soil components including nutrient uptake by the plant. I'm sure I'm forgetting something but these natural changes should be considered also. The use of slow release fertilizer may be better than using a water soluble for this reason.
Just brainstorming here. I'm wondering if a PH meter might also have these faults. Time for a test!

I've used cheap ones and never had much luck. Didn't bother to buy the expensive ones because there are better ways to judge the soil moisture.