Monday 5 December 2011

Know your onions (and their predators!)

This is a photo of a fine specimen we grew in 2009. Last year we had no onions at all. All the onions (Ailsa Craig) and shallots (saved successfully for many years) went rotten and soggy. We put it down to the very cold and wet summer. We had plenty of leeks though. In previous years we'd had a really good harvest which kept us in onions all year. They kept really well hanging on strings in the (unheated) conservatory.

Undaunted, this year we sowed more Ailsa Craigs and leeks (Musselburgh) and planted them all out lovingly. We bought more shallots (Longor). The shallots were good - we lifted them in August and we got some onions, but about half were showing signs of rot again. But the real horror came when we checked the leeks. They hadn't really been growing well. We thought this was due to the drought earlier in the year. But when I pulled up a few of the biggest ones, with a view to Cock-a-leekie soup, I found they were infested with little white grubs. Research on Google quickly came up with "allium leaf miner" which is apparently a fly which lays eggs a couple of times a year in onions, shallots and leeks (all alliums). The RHS has a good description here

This nasty beastie seems to be a new migrant to our shores and we in the East Midlands are particularly suffering.  The rotten onions last year were probably a result of infection following the damage by the flies.

So all the leeks got burnt. We've made the decision not to grow leeks next year, but we'll try growing onions in a different spot and under cover when we first plant them out in May. With a bit of luck we'll harvest early before the second egg-laying season.

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