Pest identification
What's eating my choy sum 'sumo'?
Cabbage aphid (Brevicoryne brassicae)
Signs: Waxy grey-green colonies in leaf axils, on flower buds, and along stems; distorted growth; honeydew.
Control: Inspect axils and flower stems twice a week; jet wash; insecticidal soap; harvest flowering stems promptly before populations build.
Flea beetle (Phyllotreta spp.)
Signs: Shot-hole peppering on seedling and young leaves.
Control: Mesh or fleece from sowing; well-watered vigorous plants outgrow damage faster.
Cabbage white caterpillar (Pieris rapae / Pieris brassicae)
Signs: Irregular holes in leaf blades; green larvae and frass.
Control: Exclusion netting; Btk spray; hand-pick.
Slugs and snails
Signs: Holes in lower leaves and slime trails at the stem base.
Control: Iron phosphate pellets; beer traps; hand-pick at night.
Keep choy sum 'sumo' pest-free
Healthy plants resist pests best. Get the basics right:
Choy Sum 'Sumo' pests — FAQ
What is eating my choy sum 'sumo'?
Choy Sum 'Sumo' produces large, vigorous bolting stems and is vulnerable to the same suite of brassica pests: aphids clustering on flower stems, flea beetles attacking seedlings, caterpillars holing the leaves, and slugs at the base. Its large stems can harbour aphid colonies in the leaf axils — inspect regularly.
How do I get rid of cabbage aphid (brevicoryne brassicae) on choy sum 'sumo'?
Waxy grey-green colonies in leaf axils, on flower buds, and along stems; distorted growth; honeydew. Inspect axils and flower stems twice a week; jet wash; insecticidal soap; harvest flowering stems promptly before populations build.
How do I get rid of flea beetle (phyllotreta spp.) on choy sum 'sumo'?
Shot-hole peppering on seedling and young leaves. Mesh or fleece from sowing; well-watered vigorous plants outgrow damage faster.
How do I get rid of cabbage white caterpillar (pieris rapae / pieris brassicae) on choy sum 'sumo'?
Irregular holes in leaf blades; green larvae and frass. Exclusion netting; Btk spray; hand-pick.
How do I get rid of slugs and snails on choy sum 'sumo'?
Holes in lower leaves and slime trails at the stem base. Iron phosphate pellets; beer traps; hand-pick at night.