Verdia · Library
Leaf spots and lesions
Record the shape, border and colour of leaf marks, and see how Verdia routes 41 fungal and bacterial genera, from Septoria to Xanthomonas, to leaf spot.
How leaf-spot names are routed
Verdia's leaf-spot group lists 41 genera. Most are fungi, such as Septoria, Cercospora, Alternaria, Colletotrichum, Diplocarpon and Venturia, but two bacterial genera, Xanthomonas and Pseudomonas, are also in the list. Unlike most groups, this one has no fallback keywords. A family-level name with no listed genus therefore matches nothing, and the app shows no steps for it.
The match uses only the first word of the scientific name, so the species part does not change the group.
Under a confident result the app writes Probably, followed by the name, and then lists the steps under What to do with a note to read the label of any product before use.
Observation steps
- Photograph the marks on both leaf surfaces, then the whole plant.
- Record each mark's shape, border and colour, and where on the leaf it sits.
- Write down the date the marks first appeared.
- Keep a timeline of light, watering and recent changes, since houseplant marks can also have environmental causes.
Reading a Diplocarpon result
If Pl@ntNet returns Diplocarpon rosae at 47 percent, the genus diplocarpon is on the list and the leaf-spot steps appear. This page repeats two: removing spotted leaves and clearing away fallen ones, and keeping water off the leaves by watering at the base early in the day. The third app step is about hygiene and when to treat, and is held back.
- Name returned
- Diplocarpon rosae
- Top score
- 47%
- Rule that matched
- genus diplocarpon
- Leaf-spot steps shown here
- 2 of 3
A result of Mycosphaerellaceae at the same score would show the name but no steps, because the family is not a listed keyword.
Where records go wrong
- Photographing only the top of the leaf, when the lower surface can look different.
- Reading a bacterial genus such as Xanthomonas as a fungus because it shares the group.
- Skipping the date, which makes it impossible to tell whether marks are spreading.
- Assuming every brown mark is a disease rather than a watering or light change.
What the group does not decide
The label groups names for general steps and does not diagnose the mark. The RHS guide to helping a poorly houseplant, listed below, covers the wider causes of leaf marks; the ASPCA list is the reference for pet safety.