My leeks are looking beautiful at the moment. All standing straight like a line of Welsh soldiers waiting to be deployed to service in the kitchen.
This time last year the scene was very different. All season they were doing well until mid-September. It wasn’t until I was using them in the kitchen that I noticed they had been attacked by allium leaf miner – a little brown grub.
Only 3mm long, Allium Leaf Miner damage leeks by leaving vertical tunnels as they eat the inner layers – exposing the plants to further infection from other diseases and mildew.
There are two key points of the year when the Leaf Miner attack, March to June and September to November. During these periods I cover the crop with horticultural fleece and use anchor pegs to secure it from high winds; ready made Fleece Tunnel Kits are available. After all the work of sowing the seeds, transplanting and nurturing the crop, it would be foolish to ignore these warnings.
An early warning are small holes in the leaves, this is when the female fly sucks sap from the plant prior to laying the eggs and destroying the crop.
In addition to leeks, other crops which can be effected are chives, garlic, onion and shallots.