Japanese onion and the miner

[baggyman]

I am lucky enough to be in an area where the allium leaf miner is rife. So to try and guard against it I have started my Japanese onions in the greenhouse.
These miners are supposed to fly twice a year, now and march/april.
Would I have any chance of decent onions if I grew them in the greenhouse and planted out in May next year after the threat has passed?

[wiccanlou]

I'd be interested to know this one as I am planning on jap onions myself

[SarzWix]

I don't know if it'd be worth planting them out in May - wouldn't they be nearly ready to harvest by then? Could you plant them out and cover with a fleece tunnel or something like that to keep the miners out?

[Snadger]

Worth an experiment with some of them but I would personally plant the majority outside.

I may be wrong but I think they would grow 'leggy' and soft in the greenhouse.

Having said that it's my intention to utilise my greenhouse through the winter this year. Anything I plant outside from now on will also have a few planted inside. After all, why waste all that sheltered accomodation for plants in the winter period? If nothing else it should give a succession as the indoor plants will mature sooner methinks?

[vegnut]

I'm gonna try winter Gem Lettuces in the greenhouse this winter, just to see how they fare. Sorry, a bit off topic there. I would certainly put the japs outside and cover with fleece/ enviromesh or the likes.

[Two_Sheds]

Allium Leaf Miner

The allium leaf miner is a pest of Allium crops, particularly onions, spring onions, garlic and chives and potentially of ornamental Allium plants. It mines the leaves and bulbs, making the plants soft and susceptible to bacterial and fungal infections, such as white rot. Heavy infestations completely destroy plants. Adult flies are about 3mm long with a black and yellow underside and black legs with yellow ‘knees’.

The pest is causing widespread damage to crops in an increasing number of European countries. The first UK outbreak was discovered in December 2003 in Wolverhampton.

[Two_Sheds]

Leek Moth

I get leek moth attacks every year, here on the East Coast. My leeks have been devastated in the last few weeks, and I haven't the heart to tackle them yet, so they are just rotting in the ground.

The leek moth has 2 generations with damage occurring May-June and August-October. The 2nd generation is more abundant.
The caterpillars are pale yellowish-green with brown heads and up to 12mm long. When fully fed the caterpillars emerge and pupate inside net-like silk cocoons spun on the foliage. Adult moths emerge in early autumn and overwinter in sheltered places. Previously a coastal problem, leek moth is now found further inland in southern and eastern England.


No effective insecticide is available to home gardeners for use on leeks and onions. Growing plants under fleece, such as Enviromesh, will prevent the moths laying eggs. Keep leeks watered in summer to ensure strong growth; larger plants are more tolerant of damage and can survive to produce usable crops.

Interestingly, my larger leeks have been worst hit.
That's yet another crop that now needs to be grown under cover. My allotment will look like a curtain factory instead of a garden

[baggyman]

I think I'll keep them in the greenhouse until the first wave of miners have gone....end of Oct and then plant out, covering them end of Feb onwards.

[Protea]

Theres no harm in starting them off in modules now - they'll grow a strong root system ready for planting out, but i wouldn't wait until May to plant then out - plant them out in a month or so before the frost really hits and make sure you harden them off before you plant them otherwise it will be a rather nasty shock for them!

[Terryr]

Jap onions and white root rot

Hi there I have to grow my onions in growbags due to this disease.
Has anyone had experience of doing this? I was thinking of keeping them in my greenhouse over-winter. What's your thoughts on this?

Terry
Paisley
Scotland

[Two_Sheds]

Google does: http://www.defra.gov.uk/planth/pestnote/allium.pdf

[Sheepish]

There was a mention of it near the end of Friday's Gardeners World, but it didn't say much. I assume it will be available on I player.

[Phil-Allotment]

Beware!!

Have a look at this little critter, the Allium leaf miner (phytomyza gymnostoma) this fly needs to be taken seriously, he attacts particularly onions, spring onions, garlic and chives.

Came to light in Wolverhampton in the West Midlands some twelve months ago and has now started spreading across the Midlands.

For more information on this critter go to:-

The Royal Horticultural Society - Research: RHS Science Exchange

Hope this info is of help to you.

[SarzWix]

Thanks for that Phil Looks like an Enviromesh cover would be a good idea for onion beds in that area? So far as I know, it hasn't made it to Yorkshire yet.

[blackcatlois]

I put an enviromesh tunnel over my onions last year, after losing them all to this pest the year before and it worked a treat and will certainly cover them like this in future