Fertiliser scorch
Damage caused by too much fertiliser rather than too little: brown crisp leaf tips and margins, a white crust on the compost surface or pot rim, and roots that are brown at the tips. It is easily mistaken for underwatering, and watering more makes it worse if the feed continues.
What brings it on
Feeding at more than the stated rate, feeding a plant that is not actively growing, or feeding compost that is already dry. Salts also accumulate over time in a pot that is never flushed through.
source
Sourced guidancemoderate confidence
- Royal Horticultural Society: Fertiliser damage
Checked 2026-08-13
Preventing it
Ordered by how much difference each measure actually makes, not by how often it is repeated.
- Feed at the rate on the label and not above it, only while the plant is in active growth, and always onto compost that is already moist.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Feeding plants
Checked 2026-08-13
Dealing with it once it is there
- Stop feeding and flush the pot through with plenty of clean water, letting it drain freely, to wash accumulated salts out. Scrape off any crust on the surface first.
source
Sourced guidancemoderate confidence
- Royal Horticultural Society: Fertiliser damage — recovery
Checked 2026-08-13
Signs that lead here
Each of these lists the other things that produce the same sign, and how to tell them apart.
On sprays and treatments
GrowingHQ does not tell anyone what to apply, at what rate, or how often. Pesticide approvals differ by country, change without notice, and the product label is legally binding — it is also the document you are holding. What is described here is cultural and physical control, which is what a home grower can act on without a label in front of them.
Plant-specific guides
Where this is one of several causes that look alike on a particular plant, GrowingHQ publishes the differential rather than the general answer.