Standing over a pot, meter in hand

Your meter gave you a number. Now what?

Push the probe in, point your phone at the display, and Plant Tender tells you — plant by plant — whether to water today or leave it alone. No calendar. No sensor in every pot. And no pretending the meter is never wrong.

Start free What does my reading mean? Three plants free, forever. No card.
Someone checking a monstera with a soil meter beside a bright window

Why schedules fail

A pot doesn't know what day it is.

The same plant dries out in three days by a south window and stays damp for two weeks in a cool corner. A fixed schedule treats them identically, and you find out which one was wrong months later.

Calendars can't learn

Miss a Tuesday and the app has nothing to say. It never knew what was happening in the soil in the first place.

Sensors don't scale

A smart probe in every pot is priced for three plants on a shelf. Past a dozen, the maths stops making sense.

A number isn't an answer

A meter says 40%. Fine for a fern, a slow disaster for a succulent — and nobody has that memorised for forty plants.

How it works

One meter. One walk around the house.

Add a plant once. After that it's a few seconds per pot, whenever you have a spare ten minutes.

1

Photograph it

One clear shot. Plant Tender names the species and fills in its moisture, light and soil-temperature thresholds.

2

Take a reading

Push the probe into the soil and point your phone at the display. Plant Tender scans the numbers — you type nothing.

3

Get a plain answer

Water it, or leave it alone. Weighed against what that plant needs — and hedged out loud when the reading isn't solid enough to carry a firm answer.

4

Watch the curve

Readings stack up into that pot's drying curve. The same meter in the same pot is consistent with itself, so the direction is trustworthy even when one number isn't.

Someone holding a phone up to scan the display of a soil meter pushed into a monstera pot, other houseplants around A phone held in front of an Italian cypress, showing the plant's detail screen with a "concerning" assessment, in a Spanish-style courtyard

The part we could have left out

Cheap meters lie. That's the reason this exists.

A soil meter is not a moisture sensor. It's two dissimilar metal probes making a small current, and what the display reports is conductivity — which follows the water only when nothing else about the pot changes. Something else always changes.

Fertiliser reads as wet

Fertiliser and tap-water mineral buildup raise conductivity on their own. If a pot never reads low, suspect salts before you suspect the plant.

Chunky mix reads as dry

In bark, perlite and pumice the probe bridges air pockets as much as soil — so aroids and orchids, the plants people fuss over most, get the least trustworthy number.

Depth changes the answer

Every pot holds a saturated layer at the bottom. The same probe pushed to the same depth is measuring two different things in a shallow pot and a deep one.

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

0100

Your meter reads 40%

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

below the number they want

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.

So we don't hand you a target number and call it an answer. A reading is a band, not a point. Tell us what the pot is filled with and how deep it is — one tap each, and no other app asks — and we'll say how far to trust today's number, which failure above is the one likely to be biting, and where to put the probe so the next reading is comparable to this one. Then watch the direction: your meter, in your pot, over a couple of weeks is consistent with itself even when the absolute number isn't. That curve is the thing worth trusting, and it's the one thing a dial in your hand can never show you.

See what your reading means

Why it exists

I killed a lot of plants before I built this. Not on purpose, and not for lack of trying.

I was following the schedule an app gave me — water this one Tuesday, mist that one Thursday — and overwatering some plants into root rot while others went bone dry. Then I went on holiday, handed my plants to someone else, and came back with no idea what had been done to them.

So I bought a cheap four-in-one probe and hit the last wall: a pile of readings and no idea what they meant. That's the whole gap Plant Tender fills. One inexpensive meter, and software that already knows what the numbers mean for the plant in front of you.

— Stephen, who built this for himself first. Read the whole story

A wooden shelf full of houseplants — pothos, monstera, snake plant, succulents — in real home light beside a window

What you'll need

Two things, and you already have one.

A four-in-one soil meter showing moisture, temperature, light and pH readings, resting on a warm wooden surface

A four-in-one soil meter

  • Any soil meter works — you are not locked to one device.
  • No Bluetooth, no pairing, no app of its own. You just read the display.
  • One meter, bought once, for the whole house.
See the meter I use

If you buy through this link I earn a small commission, at no extra cost to you.

A phone held up in a bright plant-filled room, showing the Plant Tender app with a list of plants in Laura's Home

The phone in your pocket

  • Runs in any browser. Installs to your home screen like an app.
  • Sign in with Google, or set a password.
  • Share the house with your partner or whoever's watching the plants while you're away.
Start free

Pricing

Three plants free. Everything else, $29.99 a year.

Every feature is on both plans. The only difference is how many plants you're keeping alive.

Free

$0 forever
For a windowsill's worth.
  • Up to 3 plants per home
  • Photo ID, meter scanning, diagnosis
  • Invite your whole household
Start free

Pro unlimited

$29.99 / year
Or $5.99 monthly — the year saves 58%.
  • Unlimited plants, every room
  • Everything in Free
  • Cancel anytime — your history stays
Start free, upgrade later

Compare the plans and read the FAQ →

From the blog

The story behind the app.

Notes on building Plant Tender, keeping plants alive, and reading a meter for what it's actually telling you.

YAMRON 4-in-1 Soil Moisture Meter: How to Use It Right

I stood over my fiddle leaf fig with the manual in one hand and the probe in the other, doing the thing you're not supposed to do with a new tool: following the instructions to the letter. Insert 4 inches. Take five readings. Check the display. I pushed the probe down exactly 4 inches, felt it hit resistance somewhere near the bottom of the pot, and watched a little grit come up through the drainage holes when I pulled it back out. The pot was maybe five inches deep. I had just rammed a metal probe into the bottom tray.

Read the story →

How deep to put a moisture meter in the pot

The first time I used a moisture meter, I jammed it maybe an inch into the topsoil of my fiddle leaf fig, right up against the trunk, and got a reading of 15%. Bone dry, I figured. I watered. Two days later I did the same thing — different spot, different depth, whatever felt natural — and got 38%. I remember standing there genuinely confused, like the plant had changed its mind about being thirsty in forty-eight hours. It hadn't. I had just measured two completely different parts of the pot and called them the same number.

Read the story →

Why Do Two Moisture Meters Give Different Readings?

didn't matter. I still remember standing in my kitchen holding two moisture meters over the same pot of pothos, one in each hand like I was dowsing for water, and getting two different answers. The cheap analog dial I'd had for years said MOIST, needle sitting happy in the middle of its arc. The newer digital probe I'd just bought said 38%. I stood there doing math that made no sense — is 38% the same as "moist"? Is it drier? Wetter? — like I'd been handed a thermometer in Celsius after a lifetime of Fahrenheit and told to just eyeball it.

Read the story →

Moisture Meter Says Wet But Soil Feels Dry: Why That Happens

My fiddle-leaf fig sat by the east window looking fine, if a little dusty, on a Tuesday morning when I stuck the probe in out of habit. The screen said MOIST 61%. I stared at it, then stuck two fingers into the top inch of soil, which crumbled off dry as chalk dust. Sixty-one percent. My fingers said this plant hadn't been watered since the Clinton administration. The meter said don't you dare.

Read the story →
See all posts

From real users

What people say when it works.

These are signed-in Plant Tender users — no bots, no bought reviews, no polished quotes. Verified means the person writing it has plants in the app.

I’ve been using the app, and I’m honestly amazed at how helpful it is, especially for someone like me who doesn’t know much about plants.
— ClaudiaVerified user
Great suggestions accurate descriptions
— DebbieVerified user
Love how easy it is to add plants and quickly diagnose
— DrewVerified user

Your plants have been telling you all along.

Now you can hear them. Add your first three in about five minutes.

Start free