The moisture meter chart

Your meter says 4. Which of your plants actually needs water?

Drag the needle to whatever your own meter reads, tell it what the pot is filled with, and every plant in our dataset sorts into thirsty, fine, or too wet. All three meter scales. Every number free.

Plant Tender plant-tender.com/moisture-meter-chart

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Your meter reads 4

Tell us the mix and the pot and every number below shifts to match — a cheap probe reads differently in chunky bark than in dense soil.

Water these 3

at or below their threshold

  • Boston Fern
  • Calathea
  • Maidenhair Fern

Leave these alone 34

inside their healthy band

Too wet for these 7

wetter than they tolerate

These are conductivity probes, not moisture sensors: fertiliser salt reads as wet, air pockets read as dry, and two meters in one pot disagree. Treat every number here as a band, and trust the direction it moves over a week more than any single reading.

Every species in our dataset, on all three meter scales — and what the mix does to the number. Nothing here is gated.
…in chunky mix …in dense soil, shallow pot 1–4 dial 1–3 chart Percent At your reading
African VioletStreptocarpus ionanthus 4–7 3–6 5–8 2–3Moist to Wet 2Moist 35–65% In the healthy band
AlocasiaAlocasia amazonica 4–7 3–6 5–8 2–3Moist to Wet 2–3Moist to Wet 40–68% In the healthy band
AloeAloe vera 1–4 1–3 2–5 1–2Dry to Moist 1–2Dry to Moist 10–35% Wetter than ideal
AnthuriumAnthurium andraeanum 4–7 3–6 5–8 2–3Moist to Wet 2–3Moist to Wet 38–68% In the healthy band
Areca PalmDypsis lutescens 4–7 3–6 5–8 2–3Moist to Wet 2–3Moist to Wet 38–68% In the healthy band
Arrowhead PlantSyngonium podophyllum 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 32–62% In the healthy band
Baby Rubber PlantPeperomia obtusifolia 2–5 1–4 3–6 1–3Dry to Wet 1–2Dry to Moist 20–50% In the healthy band
Bird of ParadiseStrelitzia nicolai 4–7 3–6 5–8 2–3Moist to Wet 2Moist 35–65% In the healthy band
Boston FernNephrolepis exaltata 5–8 4–7 6–9 2–4Moist to Soaked 2–3Moist to Wet 45–75% Thirsty
BromeliadGuzmania lingulata 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 30–60% In the healthy band
CalatheaGoeppertia orbifolia 4–7 3–6 5–8 2–3Moist to Wet 2–3Moist to Wet 42–70% Thirsty
Cast Iron PlantAspidistra elatior 2–6 1–5 3–7 1–3Dry to Wet 1–2Dry to Moist 22–55% In the healthy band
Chinese EvergreenAglaonema commutatum 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 30–60% In the healthy band
Chinese Money PlantPilea peperomioides 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 28–58% In the healthy band
Christmas CactusSchlumbergera truncata 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 25–55% In the healthy band
Corn PlantDracaena fragrans 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 25–55% In the healthy band
CrotonCodiaeum variegatum 4–7 3–6 5–8 2–3Moist to Wet 2Moist 38–65% In the healthy band
Dragon TreeDracaena marginata 2–5 1–4 3–6 1–3Dry to Wet 1–2Dry to Moist 22–50% In the healthy band
Dumb CaneDieffenbachia seguine 4–7 3–6 5–8 2–3Moist to Wet 2Moist 35–65% In the healthy band
EcheveriaEcheveria elegans 1–3 1–2 2–4 1–2Dry to Moist 1Dry 8–30% Wetter than ideal
English IvyHedera helix 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 32–62% In the healthy band
Fiddle Leaf FigFicus lyrata 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 30–60% In the healthy band
Heartleaf PhilodendronPhilodendron hederaceum 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 28–58% In the healthy band
HoyaHoya carnosa 2–5 1–4 3–6 1–3Dry to Wet 1–2Dry to Moist 20–50% In the healthy band
Inch PlantTradescantia zebrina 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 30–60% In the healthy band
Jade PlantCrassula ovata 1–4 1–3 2–5 1–2Dry to Moist 1–2Dry to Moist 10–35% Wetter than ideal
KalanchoeKalanchoe blossfeldiana 1–4 1–3 2–5 1–2Dry to Moist 1–2Dry to Moist 12–38% Wetter than ideal
Maidenhair FernAdiantum raddianum 5–8 4–7 6–9 3–4Wet to Soaked 2–3Moist to Wet 50–80% Thirsty
MonsteraMonstera deliciosa 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 30–60% In the healthy band
Moth OrchidPhalaenopsis amabilis 2–5 1–4 3–6 1–3Dry to Wet 1–2Dry to Moist 20–50% In the healthy band
Norfolk Island PineAraucaria heterophylla 4–7 3–6 5–8 2–3Moist to Wet 2Moist 35–65% In the healthy band
Parlor PalmChamaedorea elegans 4–7 3–6 5–8 2–3Moist to Wet 2Moist 35–65% In the healthy band
Peace LilySpathiphyllum wallisii 4–7 3–6 5–8 2–3Moist to Wet 2–3Moist to Wet 40–70% In the healthy band
Ponytail PalmBeaucarnea recurvata 1–4 1–3 2–5 1–2Dry to Moist 1–2Dry to Moist 10–35% Wetter than ideal
PothosEpipremnum aureum 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 25–55% In the healthy band
Prayer PlantMaranta leuconeura 4–7 3–6 5–8 2–3Moist to Wet 2–3Moist to Wet 40–70% In the healthy band
Rubber PlantFicus elastica 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 28–58% In the healthy band
Snake PlantDracaena trifasciata 1–4 1–3 2–5 1–2Dry to Moist 1–2Dry to Moist 12–40% In the healthy band
Spider PlantChlorophytum comosum 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 30–60% In the healthy band
String of PearlsCurio rowleyanus 1–3 1–2 2–4 1–2Dry to Moist 1Dry 8–30% Wetter than ideal
Umbrella PlantSchefflera arboricola 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 28–58% In the healthy band
Weeping FigFicus benjamina 3–6 2–5 4–7 2–3Moist to Wet 1–2Dry to Moist 30–60% In the healthy band
Zebra HaworthiaHaworthiopsis attenuata 1–3 1–2 2–4 1–2Dry to Moist 1Dry 8–30% Wetter than ideal
ZZ PlantZamioculcas zamiifolia 1–4 1–3 2–5 1–2Dry to Moist 1–2Dry to Moist 12–40% In the healthy band

Why this is a dial and not a table

Because the question people actually have is not "what should a monstera read". It is "my meter reads 4, in chunky aroid mix, in a ten-inch pot, four days after I watered it — do I water it again?" That question has four variables, and the honest answer changes when any of them changes.

Every moisture chart on the internet answers the first question. It is the easier one, and it is the one that is nearly useless standing over a pot with a probe in your hand. So this page answers the second one, and the price of that is that you have to move something.

The three scales, and why nobody prints all of them

There is no standard. The cheap four-in-one probe most people own prints 1–10. The Luster Leaf-style analog dial prints a needle across four labelled zones — dry, moist, wet, soaked. The one competing chart in this niche uses 1–3. A few digital meters read 0–100%.

None of them are calibrated to anything. They are galvanic probes: two dissimilar metals, a current between them, and an arbitrary scale silk-screened on the housing. So the table above prints every band on all four, which is the only way to make one number usable to someone holding a different meter — and it is the reason to treat any conversion as a band rather than an equals sign.

What your soil does to the number

This is the part every other chart omits, and it is larger than the difference between many species.

The counterintuitive one is that the height of the saturated zone is set by the soil's particle size, not by the pot's dimensions — which is why the same mix at the same probe depth reads high in a short pot and low in a tall one. Pick your mix and depth in the dial above and every number on the page shifts accordingly.

Fertilizer and tap-water mineral buildup also read as "wet" — if a pot never reads low, suspect salts before you suspect the plant.

How to take a reading that is worth comparing

Roughly two-thirds of the way down the pot, midway between the stem and the rim, angled slightly away from the centre. Push it in slowly — a probe that hits a root reads the root. Read it after about a minute, not instantly. Then take the next reading in the same spot, at the same depth, with the same meter, or the two numbers are not comparable to each other and none of this applies.

Wipe the probe dry afterwards. These things corrode, and a corroded probe reads low and then stops reading at all. That is not a defect; it is how a galvanic cell works.

Common questions

What should a moisture meter read for houseplants?

There is no single right number, which is why this page is a dial rather than a figure. Most foliage houseplants want water somewhere between 2 and 4 on a 1–10 probe, but a snake plant wants to reach 1 before you touch it and a fern is unhappy below 4 — a threefold difference between two plants on the same shelf. Set the dial above to your own reading and the whole dataset sorts itself around it.

My meter reads 1–10 and this chart says percent. How do I convert?

Every number on this page is printed on all three scales that actually ship — the 1–10 four-in-one probe, the 1–4 analog dial with its DRY/MOIST/WET zones, and the 1–3 scale used by the one competing chart — plus percent for meters that read 0–100. Pick your scale in the dial and everything switches. Do treat the conversion as a band rather than a point equivalence: these are conductivity probes with arbitrary printed scales, and no two manufacturers calibrate the same.

Why does the same plant need a different reading in different soil?

Because the meter is not measuring water. It is measuring how easily a current crosses between two dissimilar metals, and how easily that happens depends on what is touching the probe. In a chunky bark or aroid mix the probe is bridging air pockets as often as soil, so it reads about a point low. In dense potting soil in a shallow pot the probe tip sits inside the permanently saturated zone at the bottom, so it reads about a point high. Same plant, same true moisture, different number — which is why the mix and pot selectors move every value on this page.

Why does my moisture meter always read wet?

Fertilizer and tap-water mineral buildup also read as "wet" — if a pot never reads low, suspect salts before you suspect the plant. A pot that never drops below the middle of the scale is usually telling you about mineral buildup or about drainage, not about water. Flush the pot thoroughly, wait a week, and watch whether the number moves at all — a reading that will not fall is a different problem from a reading that falls slowly.

Is a $12 moisture meter accurate enough to trust?

Not in absolute terms, and no amount of money fixes that at this price point — two probes in the same pot routinely disagree by a point or more. What a cheap probe is genuinely good at is relative measurement: the same meter, in the same spot, in the same pot, read over several weeks, tracks that pot drying out reliably. That is why this page ends where it does — one reading cannot be trusted, and the curve can.

Do I have to give you an email address to get the chart?

No. Every number is on this page, in the table, free, uncounted and unwalled. Copy it, screenshot it, print it, repost it.

One reading can't be trusted. The curve can.

Everything above is one argument. A single number off a cheap conductivity probe is not a measurement — it is a data point with a large error bar, and the size of that error bar depends on your mix, your pot, your fertiliser habits and how old the probe is. This page exists to make that error bar visible rather than to pretend it away.

What survives all of it is the direction of travel. The same meter, the same spot, the same pot, read over a few weeks, tells you how fast this specific plant in this specific room actually dries — and that is the thing that answers "do I water it", which no chart on any website can do for you.

Scan it instead of squinting at it

Plant Tender reads your meter from a photo, remembers what each pot read last time, and turns the readings into that curve — then tells you water or leave-it-be, plant by plant. Free for your first 3 plants, and it works with the meter you already own.

Try it free

Every threshold here comes from Plant Tender's per-species dataset (version 2), which is version-controlled and changes through a reviewed commit rather than an edit nobody sees — internal:plant-tender-team (published horticultural consensus; founder-reviewed, not horticulturist-verified). It is the same data the app itself uses to judge a reading, which is deliberate: a chart that disagrees with the product it advertises is worth nothing.