Use of moisture meters

(Question)

I have a new moisture meter and I am noticing that sometimes when I stick the meter in, it will show “Moist” but if I move over to another spot, it says “Dry”. So which one do I listen to and is there any way to get a more uniformed reading? I have a nice Monstera which had so many different readings today that I left it for fear I’ll overwater. Help please!

(Answer)

Hello – I don’t have any personal experience with moisture meters but I know many gardeners find them useful.  Like all devices, they do fail and they do degrade over time.  The first thing to check is that you are using the meter correctly.  Take another look at the instructions that came with your meter. To give you some additional information, I’m including a link below to a guide to watering house plants from the Missouri Botanical Garden.  The guide includes instructions on how to get accurate results from a moisture meter.

As yours is a new meter, I hope that some fine tuning of your technique will give you reliable readings. If you continue to get mixed results, you can manually test the soil moisture and compare these results to the meter’s readings. After taking a reading, stick your finger into the soil and note whether the soil is wet or dry to the touch.  House plant expert Darryl Cheng in his book ‘The New Plant Parent’ suggests another method for testing soil moisture.  He uses a blunt probe such as a chopstick to push into the soil.  Wet soil will stick to the probe.  Moist soil will feel soft as you push into it.  Dry soil will be brittle and if the soil is compacted, you’ll feel some resistance.  (If you do detect some compaction, using the probe can help to loosen and aerate the soil. Well-aerated soil will help to ensure the soil is evenly moist after watering.)

If you’d like to read more about moisture meters, I’ve copied a link below to an article by Quebec horticulturist, Larry Hodgson where he covers how moisture meters work and what can cause them to fail.

Good luck with your Monstera.

How to water indoor plants

When moisture meters fail

Other Resources Used:

The New Plant Parent, Darryl Cheng, Abrams, 2019

26/10/21