When did you last water?
"No idea."
Your Grow.
Your Knowledge.
Your Harvest.
The cannabis grow journal for ambitious growers. So every run beats the last.
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You don't remember what you did last grow.
What went well last grow?
"Didn't write it down."
How much should I water?
"I'll just guess."
How does manual weighing work?
You weigh your pot before watering — Growdy calculates your water needs from that.
How we recommend
building your grow.
01
Pot Sizes
We recommend 4 pot sizes. Each pot is fully rooted through before you size up.
0.5 L
2 L
7 L
15 L
02
Watering Rhythm
Water every 3 days. This gives the app enough data points to make your recommendation more precise with every watering.
Mon
Thu
Sun
Seedling in 0.5L Pot
You weigh the pot + dry soil. Your starting point.
Pot Size
0.5 L
Dry Weight
250 g
0.5 L
First Watering · 0.5L Pot
The first time, you enter the amount yourself. From the next watering on, the app calculates it for you.
Weight Before Watering
320 g
Water Amount
100 ml
Based on: dry weight 250 g
How we calculate
your water needs.
You weigh again 3 days after the last watering. The app calculates your daily consumption — and gives you the exact amount your plant needs until the next watering.
Last weight before watering
320 g
Weighed today Input
260 g
Consumption · per day
≈ 53 g
Consumption · 3 days
160 g
Recommendation today
160 ml
= Consumption for the next 3 days
First Repot · 2L Pot
More soil, more weight. You measure the new dry weight once.
New Dry Weight
850 g
First Watering Recommendation
≈ 400 ml
≈ 20% of pot volume as a starting value
2 L
Second Repot · 7L Pot
The plant grows, the pot grows with it.
New Dry Weight
2,800 g
First Watering Recommendation
≈ 1,400 ml
≈ 20% of pot volume as a starting value
7 L
Final Pot · 15L
No more repotting from here. This base stays until harvest.
New Dry Weight
6,000 g
First Watering Recommendation
≈ 3,000 ml
≈ 20% of pot volume as a starting value
15 L
Flowering · Week 2
Dry weight now increases week by week.
Weight Before Watering
5,400 g
Recommended Amount
≈ 3,600 ml
= Consumption for the next 3 days
Dry weight: 6,100 g ↗ +100 g
Flowering · Week 5
Peak growth. The app adjusts the recommendation automatically.
Weight Before Watering
6,300 g
Recommended Amount
≈ 3,400 ml
= Consumption for the next 3 days
Dry weight: 6,400 g ↗ +400 g
That was weighing with Growdy.
You didn't just water — you understood.
Grow complete
Growdy knows your plant.
Your gut feeling —
now with numbers.
Growdy turns your gut feeling into numbers. In the end, you don't just have buds — you have knowledge.
Structured Journal
Every entry with date and photo.
Photo Timeline
Watch growth unfold, photo by photo.
Watering Recommendation
Calculated from weight and history.
Fertilizer Plan
Recognize phase, calculate dose.
Harvest Archive
Every grow saved. Reproducible.
Knowledge that grows with you.
1Watering Intelligence
Never guess
Never guess
how much to water again.
Enter your pot weight. Growdy calculates the recommended water amount from dry weight and water loss.
How Growdy calculates it
Yesterday
3,400g
−
Today
2,830g
=
Consumption
570ml
Recommended Amount
Today · Flowering Wk. 3
1,140ml
2Automatic Fertilizer Plan
Your personal
Your personal
fertilizer plan. Automatic.
Recognize phase, calculate dose. Week by week, until flush.
Today, Apr 3
Fertilizer Schedule
BioBizz · Flowering Wk.3
●
Water
3.0L
01
Bio·Grow1.0 ml/L
3.0ml
02
Bio·Bloom2.0 ml/L
6.0ml
03
Acti·Vera3.0 ml/L
9.0ml
04
Top·Max1.0 ml/L
3.0ml
Total
21ml
From your schedule
#0042
Same for Plagron and BioCanna.
3Smarter Entry
Watering and fertilizing.
Watering and fertilizing.
In one step.
Enter your pot weight — get the water and fertilizer recommendation instantly. In one step.
4Harvest Archive
Your grows.
Your grows.
Your experience.
Harvest, duration, retrospective. A memory that never forgets.
- Harvest in grams + star rating
- Duration in weeks + phase history
- Retrospective: what went well
- Compare grows & improve
5Strain Hub
Your strains.
Your strains.
Your knowledge.
Flowering time, THC, aroma – all in one place. Build your personal strain library.
Three steps. Nothing more.
Create a grow
Name, substrate, fertilizer, plants.
~ 1 min02
Log entries
Watering, measurements, phases. Fast and structured.
~ 30 sec03
Get better
Compare runs. Use recommendations. Get better.
Every runBuilt by a grower.
I was fed up with notepads and guesswork when growing cannabis. So I built the app I wanted for myself — one that thinks ahead and forgets nothing.
Danny
Founder · Growdy
Your next run
will be your best.
Your next run
will be your
best.
Get it free now. Your next run doesn't start from zero.
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