Quick verdict
A moisture meter with a 36 inch, 5/16 inch thick metal stem and a T-handle, that pushes into the core of a large compost pile, a windrow, a raised bed or a tree root zone and reads wetness on a 0 to 10 scale after calibrating to the material, running on one AAA battery. A compost pile that is dry in the middle stalls and one that is sodden goes anaerobic, and neither shows from the outside. Three feet of stem reads where it matters. It also checks deep bed moisture and the root zone of a newly planted tree.
Strengths
- Thirty-six inch stem reads the core of a large pile
- Thick 5/16 inch stem does not bend in dense compost
- Calibrates to the material; 0 to 10 scale
- T-handle for pushing and pulling
- Rugged metal construction
Weaknesses
- Relative scale, not a percentage
- Needs calibration each time the material changes
- Long for a small bin; the 15 inch suits those
The overall YardToolLab Score is out of 100. Section scores are out of 10.
The Outside of the Pile Lies
A compost pile that looks damp on the surface can be bone dry a foot in, and a pile that looks dry can be a swamp at the core. The outside tells nothing. Reotemp’s 36 inch meter is a thick metal stem on a T-handle that pushes to the middle of a big pile or a windrow and reads wetness on a 0 to 10 scale set to the material.
This review is based on the maker’s specifications and on how long-stem moisture meters are used in composting and deep bed work generally. We have not used this meter ourselves.
Calibrating
Compost should be as wet as a wrung-out sponge. Take a handful at that state, push the stem in and set the dial to the middle of the scale. From then on, a reading below means water the pile, above means turn it and add dry browns. Recalibrate when the material changes, as the meter reads conductivity and different materials conduct differently.
Reading a Pile
Push the stem in from the side to the core at a few points and from the top. A pile that is right in the middle and dry at the edges wants watering as it is turned; one that is right at the edges and wet in the middle wants opening up. Without the reading, both piles look the same.
Beds and Trees
Three feet of stem reaches the bottom of a raised bed and the root ball of a newly planted tree, which is the moisture that decides whether the tree lives. A surface meter says wet after watering; the long stem says whether it reached the roots.
Build
A 5/16 inch metal stem that does not bend in dense compost, a T-handle that takes a push and a pull, one AAA battery. It is the professional pattern used on commercial windrows, and a home pile is no challenge to it.
Size
Thirty-six inches is for big piles and deep beds. A small bin or a tumbler is better served by the 15 inch version.
Who Should Buy It
- Owners of large compost piles or windrows.
- Deep raised bed gardeners.
- Anyone watering a newly planted tree by guesswork.
Common Owner Complaints
Relative scale and recalibration. That is how compost moisture works; calibrate once per material.
Alternatives to Consider
The Reotemp 15 inch for bins. A compost thermometer to pair with it. The squeeze test by hand, which is what this replaces at depth.
Verdict
For a pile that is read at the core rather than the skin, a three foot stem is what it takes and this one is built for years. Calibrate to a wrung sponge, probe from the side and water or turn by the number.
Full specifications
Reotemp 36 Inch Garden and Compost Moisture Meter with T-Handle, 0 to 10 Wetness Scale FAQs
Push it into a sample of the material at the wetness you know is right, the squeezed-sponge stage for compost, and set the dial so it reads the middle of the scale. Readings above and below are then wetter and drier than ideal.
A compost pile or a windrow is three or four feet across and the outside dries while the core stays wet, or the reverse. Reading the core is what tells you whether to water or turn.
Yes, to three feet, which covers a raised bed to the bottom and the root ball of a newly planted tree.
No. It is a relative scale against your calibration point, which is how compost moisture is managed in practice.
