A watering and growth log for houseplants: fixed measurement points and photographs

Goal

Record how a potted plant is watered and how it changes, in a way that lets you, or another household with the same species, compare series without relying on memory or on impressions of "it looks bigger".

Prerequisites

A ruler or tape measure, a measuring cup or a kitchen scale, one spot with the same light for photographs, and one log per plant. Each plant carries a label with the species as sold and your own identifier, such as ficus-01.

Steps

1. Baseline entry: plant identifier, species as labelled, pot diameter and material, soil as stated on the bag, position (room, distance from the window, compass direction if known) and the date acquired.
2. Define the measurement points once and write them into the log header: height from the pot rim to the tip of the tallest stem; number of leaves longer than a stated length; length of the largest leaf from base to tip; for trailing plants, the longest vine. Fixed definitions matter more than which points you choose.
3. At each watering, log date, time, the volume in millilitres from the cup or the mass in grams from weighing the pot before and after, whether water drained from the bottom, and any additive with the dose stated on its packaging. Record what was done, not what was intended.
4. Weekly, on a fixed weekday: the measurements from step 2 and a photograph from the same spot, with the same background and the pot turned to a marked front.
5. Events column: repotting, pruning (how much was removed), pests seen, a move, leaves dropped (count), flowering.
6. Monthly: compute growth as the difference in each measurement and put the month's watering total next to it, in a separate table; keep the raw entries untouched.

Expected result

A per-plant table where growth and watering history sit side by side, with photographs that let a reader check that a height figure meant the same thing every week.

Limits and test basis

Proposed template; no result about watering frequency or plant condition is claimed, and no care recommendation follows from it. Light and temperature are large uncontrolled factors unless they are logged too; a plant moved to another window starts a new series. Measuring a living plant by hand carries a reading error that this protocol does not quantify; the weekly photograph is the only check on it.

Pot mass before watering

At each watering, weigh the pot before adding water and log that mass as its own field. The difference between one pre-watering mass plus the water added and the next pre-watering mass is the water lost through the plant and the soil since the last watering; it changes with light, temperature and growth, whereas the volume added mostly records a decision. With this field the monthly table can show water lost beside growth, and two logs with identical watering volumes but different drying rates become distinguishable. Water that drained from the bottom is the one term the balance cannot separate; keep the drainage yes/no field for that reason.