A grow journal for home growers

Every day of your grow, kept in one place.

Log your readings, notes and photos as you go. Grow Log Pro charts every number, tells you what to feed this week, counts down to harvest and walks you through drying and curing, so the next run is even better.

Start your journal, it's free Try the VPD calculator

For adults 21+ growing where home cultivation is legal.

Blue Dream

Tent 2 · Coco · Day 52

Flower wk 3

EC1.9mS

Humidity51%

VPD1.24kPa

Stretch is on: up 12 cm this week, so I raised the light.

VPD 1.24 kPa, right for flower

Day 52 of 9139 days to harvest

SeedVegFlowerHarvest

Example grow. Drag the slider to watch it grow.

Everything you check, without the spreadsheet

Most problems show up in the numbers a few days before they show up on the leaves. Keep those numbers together and they start telling you things.

Daily readings

pH, EC, runoff, temperature, humidity, light, water and height in under a minute. "Same as last time" fills it in with one tap.

Trends charts

Every reading charted day by day, with the target range for each stage, so drift shows up before the leaves do.

Grow-lapse

Your photos line up into a time-lapse you can play back, from seedling to harvest day.

Voice notes

Hands dirty in the tent? Tap the mic and say what you see. It's typed into your note for you.

Every plant

Track several plants in one tent, each with its own notes, height, stretch and harvest weight.

Harvest countdown

Add the breeder's flowering time and see the days left. Autoflowers too, no flip needed.

Dry and cure

60/60 drying checks, jar humidity, burp reminders, and a clear "ready to enjoy" when the cure is done.

Seed vault

Keep count of the seeds you have. Start a grow from them in one tap and see how each strain did.

Private, on any device

Only you can see your journal. Add it to your phone's home screen and it opens like an app.

Free tools, no account needed

Setup guideWhat light, fan and pots your tent needs, and a check for the setup you have. CalculatorsDLI, EC to PPM, VPD, power cost per run, drying and jar checks. Problem helperYellow leaves, spots or bugs? Pick what you see and get the likely causes.

From seed to jar, one journal

Scroll down and watch the grow happen. Each stage has its own targets, and your journal helps at every step.

Day 1Germination

Days 1–7
Germination
Log the soak date and the first root. Your grow's day counter starts here.
Weeks 1–2
Seedling
Soft light, high humidity. Readings outside the seedling range are flagged gently.
- "Same as last time" fills today's readings in one tap
Weeks 3–6
Vegetative
Topping, training, transplants. Tap what you did and it's marked on your charts.
- This week's feed from your nutrient brand's chart
- Voice notes when your hands are dirty
Flip, weeks 1–3
Stretch
Switch to 12/12 and watch the height. Your journal works out the stretch for you.
Weeks 4–9
Flower
Buds stack, VPD climbs, and the countdown to harvest begins.
- Harvest countdown from the breeder's timing
- Trichome reminders in the last two weeks
7–14 days
Dry
Aim for 60/60. Log the room and you'll know when stems snap.
2–8 weeks
Cure
Jar humidity, burp reminders, and a clear "ready to enjoy".

Feeding charts

Know exactly what to mix this week

Pick your nutrients and your journal works out this week's feed from the brand's own chart, sized to your tank. Log it in one tap, and see when the next feed is due.

Athena, General Hydroponics, Advanced Nutrients, FoxFarm, Canna, Jack's, BioBizz and Gaia Green
Full, ¾, ½ or ¼ strength, in gallons or litres
Mix your own? Save your recipe once and use it on any grow
Feeding reminders in your journal, or on your phone's calendar

Brand names belong to their owners. Grow Log Pro isn't affiliated with them.

Day 58 · Flower week 3

This week's feed

5 gal · 75%

General Hydroponics Flora Series

FloraMicro19.9 ml
FloraGro19.9 ml
FloraBloom28.5 ml

Last fed yesterday. Next feed in 2 days.

Example feeding card

Know what worked

Every run ends with a record you can learn from, so the next harvest is better than the last.

Dry yield296 g10.4 oz

Seed to harvest106days

Per day2.79 gdry

VPD on target86%of readings

Your last two runsExample

Spring run3×3 tent · 240 W · soil

118 g

Summer 4x44×4 tent · 480 W · coco

296 g

What changed +240 W of light Soil → coco VPD on target 62% → 86% 1 more week of veg

2.5× the yield. Keeping VPD on target paid off. Do it again next run.

Pro · free for everyone during early access

Learn from every run

Once you have a grow or two logged, Pro turns them into lessons: what worked, what didn't, and a record you can keep.

Compare grows

Put up to six grows side by side: yield, grams per day and per watt, how well you held VPD, and every reading on one chart.

PDF grow report

The whole grow on a few clean pages: yield, timing, setup, charts, photos and every entry. Keep it, print it or share it.

Sensor imports

Bring in your sensor's temperature and humidity history and see every day's low, average and high behind your own readings.

How thirsty is the air?

VPD tells you how hard the air is pulling water through the leaves. Slide to match your tent: the needle swings and the colour tells you at a glance. Blue is too humid, green is just right, orange is too dry.

More calculators: DLI, EC to PPM, power cost →

Know when it's time

Look through a loupe, note what you see and add a photo. Over the last weeks you'll watch the trichomes turn from clear to cloudy to amber, and pick the day that suits you.

Trichome check, day 61Example

Clear

10%

Cloudy

75%

Amber

15%

Mostly cloudy with a little amber. The harvest window is open. A few more days gives a heavier, more relaxing effect.

Questions growers ask

Does it work for soil, coco and hydro?

Yes. Choose your medium when you start a grow and the pH ranges adjust to match.

Which nutrients does the feeding chart cover?

Athena (Blended and Pro), General Hydroponics Flora Series, Advanced Nutrients pH Perfect Sensi, the FoxFarm soil trio, Canna Coco, Jack's 3-2-1, BioBizz and Gaia Green, using each brand's own published chart. Using something else, or your own mix? Save it as a recipe and it works the same way.

Can I use it on my phone?

Yes, it's made for logging standing in the tent. You can also add it to your home screen so it opens like an app: on Android or a computer choose "Install the app" from your account menu, and on an iPhone tap Share, then "Add to Home Screen".

Is it free?

Yes. The journal is free, including feeding charts, trends, photos, harvests, and the dry and cure tracker. A Pro plan is on its way for growers running more than one grow at a time, with grow comparisons, PDF reports and sensor imports. During early access, everything is unlocked for everyone.

Can I bring in data from my sensor?

Yes. Export the history from the AC Infinity, Govee or SwitchBot app (most temperature and humidity sensors can save a CSV file) and import it into a grow. The file is read on your device and only one summary per day is saved.

Can I keep more than one grow?

Yes. Keep every grow you've done, and track several plants inside each one.

Who can see my journal?

Only you. Every grow, entry and photo is tied to your account and kept private.

Is this legal to use?

Grow Log Pro is a journal for adults growing at home where personal cultivation is legal. Check the rules where you live.

Start this run's journal today.

It's free, and your next harvest will thank you.

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