Moisture meters: save your money

24 of 100 species in this database need it

Do not buy one. Put your finger two inches into the soil. 24 of our 100 species are the ones it gets sold for.

The test, before you buy anything

Put your finger two inches into the soil. That is the test. It costs nothing and is more reliable than the meter.

Do not buy this. Do not buy one. Cheap analogue meters do not measure moisture — they measure electrical conductivity, which changes with fertiliser salts as much as with water, and they drift as the probe corrodes.

Typical price $8–$20 which is why they sell — but see above. Hand-checked range, not a live price, last verified 2026-09-12. We hold no merchant relationships, so nothing here is a commission link.

What it actually is

A probe claiming to read soil moisture on a dial from dry to wet. Most under twenty dollars have no battery, which tells you they are generating current from the soil rather than measuring anything calibrated.

What to avoid

The failure mode is expensive: the meter reads dry in salty soil, you water a plant that did not need it, and you get root rot while believing you were being careful. If you want an instrument, a hygrometer for the air is worth ten times more than a moisture meter for the soil.

Species it tends to get sold for

Ironically the group most often sold a meter. These are drought-adapted species where the finger test is easiest, because they should be bone dry before you water at all.

Plant	Why it qualifies	Water	Difficulty
Snake plantDracaena trifasciata	waters every 14–21 days	14–21d	Easy
ZZ plantZamioculcas zamiifolia	waters every 14–21 days	14–21d	Easy
Corn plantDracaena fragrans	waters every 10–18 days	10–18d	Easy
Jade plantCrassula ovata	waters every 14–28 days	14–28d	Easy
Aloe veraAloe vera	waters every 14–28 days	14–28d	Easy
Zebra haworthiaHaworthiopsis attenuata	waters every 14–24 days	14–24d	Easy
Wax plantHoya carnosa	waters every 10–18 days	10–18d	Easy
Ponytail palmBeaucarnea recurvata	waters every 14–30 days	14–30d	Easy
African milk treeEuphorbia trigona	waters every 14–28 days	14–28d	Easy
Burro’s tailSedum morganianum	waters every 14–28 days	14–28d	Easy
Mexican snowballEcheveria elegans	waters every 12–24 days	12–24d	Moderate
Spineless yuccaYucca gigantea	waters every 14–24 days	14–24d	Easy
Dragon treeDracaena marginata	waters every 10–18 days	10–18d	Easy
String of pearlsCurio rowleyanus	waters every 12–21 days	12–21d	Demanding
String of heartsCeropegia woodii	waters every 10–18 days	10–18d	Easy
Golden barrel cactusEchinocactus grusonii	waters every 18–35 days	18–35d	Easy
Ladyfinger cactusMammillaria elongata	waters every 14–30 days	14–30d	Easy
Elephant bushPortulacaria afra	waters every 10–21 days	10–21d	Easy
Crown of thornsEuphorbia milii	waters every 10–21 days	10–21d	Easy
Bunny ears cactusOpuntia microdasys	waters every 18–35 days	18–35d	Easy
Ox tongueGasteria bicolor	waters every 14–24 days	14–24d	Easy
Jelly bean plantSedum rubrotinctum	waters every 12–24 days	12–24d	Easy
String of bananasCurio radicans	waters every 12–21 days	12–21d	Easy
Sweetheart hoyaHoya kerrii	waters every 12–21 days	12–21d	Easy

This table is filtered from our own species records — recorded soil recipe, humidity floor, light floor, watering interval or growth habit, depending on the product. It is not a list of things a retailer would like to sell you.

Other supplies

Perlite worth it
Orchid bark depends
Cactus and succulent mix depends
Pumice depends
Moss pole depends
Humidifier depends

Every supply →

Sources

This database's own care records for 100 species — the recorded soil recipes, humidity floors, light floors and watering intervals this table filters on. Each species entry cites its own authorities.
Missouri Botanical Garden Plant Finder — cultivation and pest records, cited per species
North Carolina Extension Gardener Plant Toolbox — pest and disease guidance
ASPCA Animal Poison Control — relevant where a product is used on a plant pets reach

Compiled and edited by Tony Valcarcel · 2026-09-12
Prices are hand-checked ranges stamped manual, not live figures, and they move with pack size. We do not accept payment for placement and hold no merchant relationships; there are no commission links on this page. How this is sourced.