Tipburn
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Fix the cause, not the leaf
No spray will help here. The trigger is soil, water supply, nutrition or temperature, so change the growing condition and judge the result on new growth, not on damaged leaves.
Not contagious
Nothing spreads from plant to plant here. Neighbouring plants showing the same signs are reacting to the same soil, water or weather, so fix the cause rather than isolating plants.
Safe to compost
No pathogen carries over on this material, so it can go on an ordinary heap with the rest of the garden waste.
When and where to look
Scout the planting once temperatures pass 24°C, in dry air below 50%.
Rule these out first
Same category, and at least one host crop in common — so they are genuinely confusable in the same part of the garden.
The signs that lead here
Full problem lists for these crops
About
Tipburn is localised calcium starvation at the fastest-growing leaf margins of lettuce, cabbage, chinese leaves and strawberries. The soil almost always has plenty of calcium; the plant simply cannot move it fast enough to a leaf edge that is expanding in hot, dry, still air.
Symptoms
Brown, dry, papery scorching along the margins of the youngest inner leaves, while older outer leaves stay perfectly green. In hearting lettuce it is hidden inside the head until it is cut, and secondary rot often follows in the damaged tissue.
Organic Treatment
Water evenly and deeply, especially in the two weeks when the head is filling, and mulch to stop the soil drying between waterings. Ventilate under glass — still, humid air stops transpiration and with it calcium movement.
Chemical Treatment
Calcium sprays are sold for this and rarely work: the calcium stays in the leaf it lands on and cannot reach the inner leaves where the damage is happening.
Prevention
Choose tipburn-resistant varieties for summer crops, avoid heavy nitrogen feeding, which drives soft rapid growth, and shade lettuce in a heatwave. Keep plants growing at a steady rate rather than in bursts.
Crops at risk
Related problems
Tipburn risk by location
Each location has a month-by-month profile computed from the weather archive: how many hours a year actually meet this disease’s thresholds.