Keeping a growing log that actually helps

Carnivorous plants respond slowly. A change in water, light or medium shows up in new growth weeks later, long after you have forgotten what you changed. A growing log closes that gap. It does not need to be elaborate; it needs to be consistent, and it needs to separate what you did from what you saw.

What to record

For each plant, keep a short header that rarely changes:

• Scientific name as labelled, and where the plant came from.
• Pot size and medium, with the date it was last repotted.
• Position: the window or bench, and the light source if artificial.
• Water source.

Then keep dated entries. The most useful habit is to write two kinds of entry and keep them visibly separate:

• Actions: anything you did. “Moved to south sill.” “Repotted into 1:1 peat and perlite.” “Fed two traps a cricket.” “Tray dry for two days.”
• Observations: anything the plant did. “Three new traps, red inside.” “Dew gone from older leaves.” “Pitcher 4 collapsed.” “Flower stalk 8 cm (3 in).”

Keeping the two apart matters because it is tempting to write conclusions instead of either: “plant unhappy with new spot” is a guess, while “no new leaves since 12 May; moved on 2 May” is evidence.

Measure a few things

You do not need instruments, but a handful of numbers makes patterns visible:

• Count new leaves, traps or pitchers per week or month. This is the single best measure of whether a plant is improving.
• Measure the longest leaf or pitcher with a ruler, in centimetres and inches if you like, every few weeks.
• Note the temperature range at the growing spot if you have a cheap min-max thermometer, especially around dormancy.
• Record the water reading if you have a total dissolved solids meter, each time you change source.

Photographs taken from the same angle, in the same light, on the first of each month tell you more than any description. Name the files with the date and plant.

Keep it honest

A log is only useful if it includes the things that went wrong. Record the week you forgot to fill the tray and the plant that died anyway. Record the pest you noticed late. If you are keeping the log in public, as this site’s experiments are, the same rule applies: a result is a result only if the method and the failures are visible beside it.

Two habits keep the log honest:

1. Write the entry before looking anything up. Describe what you see, then research it. Otherwise the reading shapes the observation.
2. Change one thing at a time where you can, and note the date. If you move the plant and change the water in the same week, the log cannot tell you which one mattered.

A format that works

Plain text or a notes app is fine. A spreadsheet with one row per entry (date, plant, type, note, measurement) works well once you have more than a few plants, because it can be sorted and filtered. Paper has the advantage that you can keep it on the bench.

A sample week for a Cape sundew might read:

Date	Type	Entry
3 Jun	Action	Moved from east sill to south sill, about 20 cm (8 in) from glass
3 Jun	Observation	6 open leaves, dew only on youngest 2; leaves green
10 Jun	Observation	Dew on 4 leaves; oldest leaf browning at tip
17 Jun	Observation	2 new leaves since 3 Jun; tentacles reddening
17 Jun	Action	Tray refilled; has been drying in 3 days now

Nothing here is a conclusion, but a month of entries like this would show whether the move to the south sill helped.

When the log pays off

The log is most valuable at exactly the moments you least feel like writing it: when a plant is declining, when you are about to change something, and in autumn when temperate species go dormant and it is hard to remember what normal looked like last year. Read the previous year’s entries before you decide a dormant plant is dead.

This site’s experiments follow the same discipline at a slightly more formal level: a stated question, a method written down before the trial starts, dated observations, and a list of limitations. The example protocols show the format.