Plant Watering Calculator
Enter the pot diameter, plant type, season and light. The calculator gives the interval between waterings, the litres to pour until it drains through, and the signs that overrule any schedule.
Plant apps send notifications on a calendar. This one computes the interval from the physics - pot volume, drink rate, resting season - and then hands authority to the only sensor that never lies: your fingertip.
How to use
- Measure the pot's rim diameter and pick the type honestly - succulents drink a third of a tropical's rate.
- Winter halves the interval; low light stretches it again.
- Check at the interval: dry two centimetres down means water until it drains, then empty the saucer.
Frequently asked questions
How often should I water a houseplant?
Tropicals in a 15 cm pot run about a week in the growing season, two weeks resting in winter; succulents stretch three times that. The interval is a plan - the top two centimetres of soil, tested by finger, is the decision.
How much water does a plant need per watering?
Enough to drain from the bottom - roughly a fifth of the pot's volume - then empty the saucer within minutes. The drain-through flushes accumulated salts and wets the whole root ball; the emptied saucer is what saves the roots.
What are the signs of overwatering?
Yellowing leaves while the soil is still wet, soft brown stems at the base, fungus gnats, and a sour smell. Overwatering kills more houseplants than drought - roots suffocate in the water the schedule insisted on.
Do plants need less water in winter?
Yes - growth halts in low light and the drinking halves with it, which is why winter is the overwatering season. Water less, stop feeding, and let the soil dry further between drinks until spring resumes.