Help! My onions!!

[Helsbells]

Hi everyone,
I need urgent advice on my onions. I naievely planted the seeds in a "2 deep seed tray, they shot up and were lovely long (bout 2") green sticks, but now all of a sudden they have flopped over and gone all saggy. They have had pleanty of water and have been in a proagator on a sunny window sill. I know now that I wasnt supposed to put them in a seed tray, but is there anything I can do to rescue them? My leeks seem to be going the same way, and my carrots dont look great either!

[the.fee.fairy]

Sounds like it might be damping off.

I think, from what i can remember, its a fungus that attacks the bottom of the stem of the seedling and unfortunately there's nothing you can do to save them.

If you get some more seeds to put in the same tray, give it a thorough clean and disinfect to make sure there are no spores or bacteria left. And make sure your compost is sterile too.

Sorry to be the bearer of bad news, but good luck with future plantings!

[Wombat]

G'Day mate,

Do they look pinched off at ground level? If so this is damping off which can happen when you get warm moist conditions and still air. Getting better air drainage will help. The ones that are pinched are stuffed I'm afraid.

If it is any consolation I plant onions into polystyrene veggie boxes full of propagating mix in autumn (I will be doing this in a couple of weeks) and then plant them out in Spring. This has worked fine for me every year for probably 10 years or more.

Nev

[Thomzo]

I've got onions in seed trays and they've also flopped over. But they're fine otherwise. No sign of damping off. I think it must just be a case of the roots not being long enough to support the leaves.

You could try potting a couple up into a long pot and see if it helps. I'm just going to wait until I can put mine out and see what happens.

Zoe

[contadino]

When we put ours in the ground (500 of them) they all flopped. However, they stood up again after a few weeks. We put it down to them not liking the move from modules to ground.

[hedgewizard]

Since onion sets are a fair proportion of my seed purchases, I decided to try growing from seed last year. Wish I'd read the Garden Organic research first, because it was bang on the money - germination and early failure rates mean that it's not a reliable way to grow onions. Module growing came out better, but shows lower weight at harvest, and a lower proportion of the harvest fit for storage.



Since it seems that sets are the way to go, I've discovered instructions on how to grow my own sets which I'll be doing this year, for planting out next. Basically this means sowing seed very closely in April (commercially precision-sown), harvesting in August when the tops start to die back. Growing them too close means that they are dwarfed by the competition for root space, hence the little bulbs. The tops and roots are twisted off once dry, and then the sets need to be graded into small (10mm-14mm), medium (14mm-17mm) and large (17mm-21mm). The larger the set, the later you plant it directly into the ground; anything bigger than 25mm will probably bolt.

Sets are stored commercially at 5 or 6 Celsius under dry conditions, but I reckon they'd be OK in net bags in my garage. They can be heat-treated to sterilise them (which prevents bolting), but it's actually useful to have a few bolt because this gives you seed for the following year.

[Helsbells]

Thankyou all for your advice, my onions have not gone pinched at the base, so I dont think thats the problem, its all very odd really, after I posted the last message last week, when I went home, they had all perked up, over the weekend the have been up and down!! Its strange, (to me anyway, having never grown them before).
I think it might be that they have shot up to quickly, the roots cant support them.
They are still alive and growing though, so thats good news, I will just keep watering them and keep an eye on them. They were under plastic, but I have taken, the plastic lid off now so that the air can get to them a bit more.
Thanks all so much for your advice, I will keep you updated.

[hedgewizard]

Anyone know what temperature to heat-treat onions sets at, and for how long? If you don't do it you lose some to bolting, but if you overdo it you don't get any sprouting at all. Help!

[Millymollymandy]

Blimey Hedgie, you're getting a bit scientific these days. Must be the chemist in you!

Actually, don't forget those commercial ones go to seed sometimes too - this year not just my red ones but some of my white ones too!

[hedgewizard]

Yesah, you're right. The Age of Aquarius is lost on me.

Commercial sets are not heat-treated unless it says so (makes them more expensive) - if you buy heat-treated ones they're much less likely to bolt.

But how do we do it ourselves???

[Millymollymandy]

Commercial sets are not heat-treated unless it says so (makes them more expensive) - if you buy heat-treated ones they're much less likely to bolt.

Oh. I guess mine haven't been treated - just a bag from the agricultural store with a label with the name of the variety, as far as I can recall!

I've never heard of heat treating so can't help you with how it is done!