TeddyGreenFingersRose black spot
Diplocarpon rosae · Mancha negra
What you see
Round black spots with feathered edges on leaves, which yellow and drop; bush defoliates from the bottom up.
Conditions
Warm wet weather; spores splash up from old fallen leaves.
Treatment
Strip and BIN spotted leaves (never compost); sulphur slows it; feed after defoliation.
Prevention
Collect every fallen leaf; mulch in spring to bury spores; water the roots not the foliage; resistant varieties.
Months: April
The thing people get wrong
Not recorded — the field is blank rather than guessed.