Troubleshooting
Leek problems — and how to fix them
Leek (Allium ampeloprasum var. porrum 'Musselburgh') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Leek rust
Bright orange pustules on the leaves, worst in damp crowded conditions. Space plants well, avoid excess nitrogen, remove badly affected leaves, and rotate crops yearly.
Leek moth / allium leaf-miner
Larvae tunnel into the shafts, causing rot and distortion. Cover crops with insect-proof mesh during the egg-laying flights to exclude the pests.
Bolting
Premature flower spikes from drought stress or early sowing make the shaft woody and hollow-cored. Keep moisture even and sow at the recommended time.
White rot
A persistent soil fungus that rots the base with fluffy white mould; plants yellow and collapse. There is no cure, so use clean ground and a long allium rotation.
Prevent leek problems before they start
Most leek issues are care-mismatch, not bad luck. Dial in the basics:
Looking for leek in general rather than its problems? Read the full leek care guide — light, water, soil and feeding.
Leek problems — FAQ
Why is my leek leek rust?
Bright orange pustules on the leaves, worst in damp crowded conditions. Space plants well, avoid excess nitrogen, remove badly affected leaves, and rotate crops yearly.
Why is my leek leek moth / allium leaf-miner?
Larvae tunnel into the shafts, causing rot and distortion. Cover crops with insect-proof mesh during the egg-laying flights to exclude the pests.
Why is my leek bolting?
Premature flower spikes from drought stress or early sowing make the shaft woody and hollow-cored. Keep moisture even and sow at the recommended time.
Why is my leek white rot?
A persistent soil fungus that rots the base with fluffy white mould; plants yellow and collapse. There is no cure, so use clean ground and a long allium rotation.