Pest identification
What's eating my choy sum 'green lance'?
Cabbage aphid (Brevicoryne brassicae)
Signs: Dense waxy grey colonies on flower buds and stems; make the edible shoots unpalatable; stunt and distort the bolting stem.
Control: Check flower stems daily as bolting begins; blast with water; spray insecticidal soap directly on colonies; harvest promptly once buds show to reduce exposure.
Flea beetle (Phyllotreta spp.)
Signs: Shot-hole damage on young leaves; seedlings most vulnerable before establishment.
Control: Row cover or mesh from sowing; keep plants well-watered and growing fast.
Cabbage white caterpillar (Pieris rapae / Pieris brassicae)
Signs: Holes and chewed leaf edges; frass on leaves and among flower buds.
Control: Exclusion netting; Btk spray on leaves and stems; hand-pick larvae.
Slugs and snails
Signs: Ragged holes at the base of plants and on lower leaves; slime trails; worst in wet conditions.
Control: Iron phosphate pellets; beer traps; hand-pick at dusk; gritty mulch around stems.
Keep choy sum 'green lance' pest-free
Healthy plants resist pests best. Get the basics right:
Choy Sum 'Green Lance' pests — FAQ
What is eating my choy sum 'green lance'?
Choy Sum 'Green Lance' bolts quickly to produce the edible flowering shoots that are its selling point, but that same rapid, tender growth is highly attractive to aphids (which love flower buds), flea beetles on seedlings, caterpillars on leaves, and slugs. Aphids congregating on the flower heads are the most commercially damaging pest.
How do I get rid of cabbage aphid (brevicoryne brassicae) on choy sum 'green lance'?
Dense waxy grey colonies on flower buds and stems; make the edible shoots unpalatable; stunt and distort the bolting stem. Check flower stems daily as bolting begins; blast with water; spray insecticidal soap directly on colonies; harvest promptly once buds show to reduce exposure.
How do I get rid of flea beetle (phyllotreta spp.) on choy sum 'green lance'?
Shot-hole damage on young leaves; seedlings most vulnerable before establishment. Row cover or mesh from sowing; keep plants well-watered and growing fast.
How do I get rid of cabbage white caterpillar (pieris rapae / pieris brassicae) on choy sum 'green lance'?
Holes and chewed leaf edges; frass on leaves and among flower buds. Exclusion netting; Btk spray on leaves and stems; hand-pick larvae.
How do I get rid of slugs and snails on choy sum 'green lance'?
Ragged holes at the base of plants and on lower leaves; slime trails; worst in wet conditions. Iron phosphate pellets; beer traps; hand-pick at dusk; gritty mulch around stems.