Herbicide Damage
Act nowGrowing conditions · does not spread · also called 2,4-D drift, spray drift, contaminated compost
Growth-regulator herbicides such as 2,4-D and dicamba cause distinctive twisting distortion at very low doses, and tomatoes are extraordinarily sensitive to them. The two routes in are spray drifting from a neighbouring lawn on a breezy day, and contaminated manure or compost made from treated hay — which can persist for a year or more.
What it looks like
New growth twisted, cupped, fern-like or strap-shaped, with stems that may spiral. Leaves take on a leathery texture and abnormally prominent parallel veins. Older leaves below stay entirely normal.
How to confirm it
- Only new growth is affected; older leaves are untouched.
- Twisting, cupping and fern-like narrowing rather than spots or mottling.
- Several unrelated plants affected at once, often on one side of the garden.
- No insects, fungus or spotting anywhere.
What to do
- 1Identify the source. If it is drift, a mildly affected plant often grows out of it once exposure stops.
- 2If it is contaminated compost or manure, the plant will not recover and the soil may need a season or more.
- 3Water well and avoid feeding heavily; forcing growth does not help.
- 4Test suspect compost by sowing beans or peas in it — they are highly sensitive indicators.
What it gets confused with
One observation settles each of these.
Mosaic also distorts growth, but adds green mottling and typically affects one plant at a time. Drift hits several plants together and does not mottle.
Aphid curling comes with visible insects and stickiness. Drift has neither.
Preventing it next time
- Ask neighbours to avoid spraying on breezy days.
- Be cautious with manure or hay of unknown origin — persistent herbicides survive composting and the animal's gut.
Plants affected
Check these two things first
- Push a finger into the soil, two knuckles deep. Wet soil plus a wilting plant means too much water, not too little — and it is the commonest reason a plant is dying. Dry soil plus crisp leaves means the opposite. The leaves look nearly identical either way, so the soil is what tells you.
- Turn a damaged leaf over. Half of all diagnoses live on the underside: fuzz means downy mildew, fine webbing means spider mites, clusters of insects mean aphids. Nothing on the top of a leaf is as informative.
Most garden problems are cosmetic and resolve without treatment. Reach for a spray last, not first.