[Flowertot]

Due to previous years' leek moth invasions, this year my leeks are under enviromesh. It is working well in terms of keeping out moths but it's clear the leeks don't get as much rain as they would without the mesh (much drier soil under there) and they are suffering from rust which is a problem I haven't had before. Could the rust be caused by being under the mesh? If so, would it help if I took it off at some stage?  Presumably the moths aren't around during the depths of winter...?

[Salmo]

You should be safe from moths now.

The sheltered conditions under the mesh may have encouraged the rust. What we need is a sharp frost or two.

[Growster...]

I've always found that rust doesn't ever completely ruin a leek, but it just looks unsightly.

You may lose the outer leaves, but on the whole, most of the plant is usually intact!

[lettice]

Never seen any moths or insects ever touch a leek. But have heard of some on here before mentioning leek moth.
But have seen the odd plant over the years get a little bit of rust. But tends to just be on the outer leaves.
Think rust occurs if you grow them too close together and too many together. I grow leeks all around the plot, say a good twenty together, but not too close.
Both my Dad and Myself are having a great year for leeks (I always grow from seed and pass plants onto my Dad)
Probably one of the best ever and are all looking very large now, seems a bit ealy for them to get to that stage already. But they always grow well and ready for picking from now till end Feb.

[mjg000]

My leeks from seeds were lovely until about 3 weeks ago when they started flopping over and when I weeded I realised that they were being chewed through.  I will look for caterpillars next time I'm down but reading up on it my guess is that my leeks have succumbed to the dreaded moth this year.  Should I get them up asap or just wait and see what's left?

[JayG]

I'd start by digging up one of the worst affected plants and assessing the extent of the damage - the leek moth larvae don't pupate inside the plant, the allium leaf miner larvae do (you can easily spot them as brown pupae lying snugly in the tunnels they have created in the leaves.)

Whichever pest it is, apart from the primary damage they cause, the plants may start to rot due to secondary fungal attacks caused by the damage. If the attack is severe, it's probably best to cut your losses by harvesting them all and freezing what you can salvage.

The allium leaf miner did attack my shallots this year too, but with a bit of TLC they recovered to crop well (they are harvested before the second, usually more serious attack of the year, which unfortunately isn't really an option with leeks.)

As you may have guessed I'm growing my leeks under enviromesh this year, and they do have some rust - I don't suppose the mesh helps, but mine usually get some rust anyway, which is definitely the lesser of the two (or is it 3?) evils.

[Flowertot]

My leeks from seeds were lovely until about 3 weeks ago when they started flopping over and when I weeded I realised that they were being chewed through.  I will look for caterpillars next time I'm down but reading up on it my guess is that my leeks have succumbed to the dreaded moth this year.  Should I get them up asap or just wait and see what's left?

When this first happened to me a couple of years ago, someone (I think it might have been MoS) suggested I cut them down to about an inch high and they would regrow a bit now that the moth or leaf miner (not sure which) would not be around so much. I did that and it was excellent advice because the leeks did regrow and although they were fairly slim, at least I got some crop.

[Salmo]

Any damage by leek moth has been done. The tiny caterpillars will have pupated on the upper leaves and hatched into tiny moths (about 6mm) which hibernate over the winter tucked under any sheltered place. They will be back in the Spring to lay their eggs.

mig000 I would leave the leeks in the ground. Last year when we were eating them after Christmas all we could find were a few tunnels. These were under the outer layers and no problem.

Leaf miner are a bigger problem as they overwinter in the leeks, either actively feeding or as pupae.

[Liverpool Brick]

Think rust occurs if you grow them too close together and too many together.

Mine are planted close together and have rust - I'll know for next year. As stated in this discussion the rust only affects the outer leaves but is there anything I can spray on to stop or reduce it? Cheers 

[mumofstig]

You can buy varieties that are resistant to rust 
They do get a little bit in a bad rust year, but not nearly as bad as some of the older varieties.

[Liverpool Brick]

I've planted Jolant and Musselburgh and according to a well known seed supplier Musselburgh " Also offers good resistance to rust and bolting". I've rust in both varieties but I shall try better spacing next year. Is there any link with moist weather conditions? I'm in Northern Ireland and the plot is about 1/4 mile from the coast. Cheers,
Andy

[mumofstig]

The RHS says there is a link to wet weather......

•Infection is worse on nitrogen-rich soils with low potassium, so take care with fertiliser applications
•Do not crowd plants, as this raises humidity and increases the likelihood of infection
•Dispose of all plant debris at the end of cropping
•Suppliers sometimes claim a degree of resistance for certain varieties, check the latest catalogues for those currently available
There are no chemicals approved for control of leek rust for gardeners.

https://www.rhs.org.uk/advice/profile?pid=214

[Liverpool Brick]

Thanks Lesley, that's useful info. especially about nitrogen and potassium. Definitely plant with wider spacing next year and apply fertiliser accordingly. I'll check RHS site, too. Thanks again, Andy

[Gardener and Rabbit]

Whenever I walk across the leek fields around here, I'm always struck by how close together the plants are growing in the rows, and also how stagnant and green with algae any puddles in those fields are.  Suggests to me there's a lot of (nitrogenous) fertiliser being used, and fungicide. The leeks are always a good size and rust-free.

[mumofstig]

Farmers have many sprays available, that gardeners are not allowed to use.

Me, I'd rather just strip off the outside leaves - than spray with chemicals