The RHS says maybe? The miner gets in the stems, but the cause of death of the plant is secondary infection and rot. I have leek moth which at least you can keep out with mesh put on when planted & kept on until the 2nd breeding season is over in October.
OH: Yes my leeks Geoff: I have had white onion rot (I think) before but that was more than 7 years ago, since when I have not grown onions on that area. But it certainly has the characteristics. Robo: Yes, and I had those brown streaks last year but the leeks didn't collapse like this. (which might mean Geoff is right). Westi: I, too, looked at the RHS site. I have brought some of the debris home but haven't steeled myself to examine it carefully.
Nothing is foolproof to a sufficiently talented fool.
Hi Stephen, we suffer from Allium Leaf Miner and have done for some years. Our leeks don't look like yours. The miner lays something like a small dark brown grain of rice, which then starts off under the first layor of leek and heads for the roots. Once there, it moves in a layer and heads back up the stem, then down again and so on, stitching it's way in. They leave long thin orange stripes where they have been and I can't see these on your photos. If you cut the leeks open, you'll find the little blighters lurking within. The plant does keel over eventually, and it stinks, but it takes some time. You can pull what you think is a healthy leek, only to find you can only eat one side of it, if you are lucky. Most have to be binned. Hope this helps.
Chantal
I know this corner of the earth, it smiles for me...
My leeks were looking pretty healthy until a week ago but are now looking As if thy could easily collapse on me. Can,t see any sign of insects. Wonder if it,s the sheer amount of rain we,ve had which is causing them to rot. Our normally fast drying soil is simply sodden.
My crop has slimy outside layers which I totally attribute to the rain. Inside is just fine but the slimy stuff outside is a nuisance & a great looking leek is a mini leek in a blink. Grateful though I have a crop & a bit of dry coming up but I doubt they can regenerate from the damage. Finally I'm glad I plant too many but objective was to have some left over & heeled in for the bees. Don't panic the globe artichokes are well happy so the bees will have a nectar source!
The black dots say yes, but not many so you may be able to retrieve something from the inside layers. I saw a pic on some site or another & they had so many black dots they would never get anything. Maybe you got attacked a bit later than them, but regardless it is disappointing. But I hope you can retrieve something, even if the upper leaves which are a bit tougher but cook them longer & perfectly OK & you still get some use from the crop which takes quite a bit of space & time, so you do want something for your investment!
I have a theory on this...i'm not totally convinced it's Leek Miner but, i'm wondering if it is more down to weather conditions this year, as some of mine are turning out to have the same symptoms. So, my theory is, it might be down to that very long dry spell of weather in the Summer, followed by some exceptionally heavy rains, that made the layers of leeks split as they swelled too quick, then constant rain, that sat in the splits ad started the leeks to rot. Just a thought....