Pansy pests and diseases: how to recognise them

At a glance

How to grow pansy · All pests and diseases

Pests

• Two-spotted spider miteFine pale stippling or mottling on the upper leaf surface; leaves may turn bronze.Also called: red spider mitePhoto: Gilles San Martin from Namur, Belgium, CC BY-SA 2.0, Wikimedia Commons

Diseases

• Downy MildewA white, grey or purple mould on the underside of the leaf, directly below each blotch, in damp weather.Photo: Christian Hummert (Ixitixel), CC BY-SA 3.0, Wikimedia Commons
• Grey mouldFuzzy grey-brown mould on decaying buds, flowers, leaves, stems or fruit in humid weather.Photo: Schlaghecken Josef, CC BY 4.0, Wikimedia Commons
• AnthracnoseRound, sunken spots on ripening fruit that darken in the centre, often with rings; in the end the whole fruit rots.Photo: Clemson University - USDA Cooperative Extension Slide Series, Public domain, Wikimedia Commons
• Cercospora leaf spotMany small, round spots with a pale brown to off-white centre and a red to reddish-purple margin.Photo: Plant pests and diseases, CC0, Wikimedia Commons

Nutrient deficiencies

• Boron deficiencyHollow stems and browning heads or curds in cabbage, cauliflower and broccoli.Photo: Jan Hinrichs-Berger, LTZ Augustenberg, CC BY 4.0, Wikimedia Commons

Which pansy problems need quick action?

These spread or do lasting harm fast; check the plants and start treatment the day you see them.

• Downy Mildew: Badly affected leaves shrivel and turn brown or yellow and fall early; plants become stunted and some may die.
• Grey mould: Small, almost translucent spots that turn brown and water-soaked; affected tissue goes soft, dark and dies, and buds and flowers shrivel.

Plants with many of the same problems

• Cucumber (4)
• Strawberry (4)
• Beet (3)
• Gerbera (3)
• Grape (3)
• Green Beans (3)
• Busy Lizzie (3)
• Lettuce (3)

Which plants each problem affects: sources

The links between these problems and the plant were checked against these pages.

1. rhs.org.uk/biodiversity/glasshouse-red-spider-mite
2. ipm.ucanr.edu/PMG/PESTNOTES/pn7405.html
3. rhs.org.uk/disease/downy-mildews
4. en.wikipedia.org/wiki/Downy_mildew
5. rhs.org.uk/disease/grey-mould
6. ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/botrytis.html
7. extension.psu.edu/pansy-diseases
8. hgic.clemson.edu/factsheet/pansy-diseases-insect-pests/
9. rhs.org.uk/prevention-protection/nutrient-deficiencies
10. en.wikipedia.org/wiki/Boron_deficiency_(plant_disorder)