Allium Problems
Im experiencing a few set backs with my Allium crops this year.
I planted shallots in Early august and allthough (according to recommendations) I planted the bulbs a little deep once things warmed up they showed through and got plenty of green health tops. But in the last month ive lost quite a few of the bunches, wilting and yellowing , pulling them up for a look has shown them to be easy to pull up with little root left.
Now ive noticed some thing Similar with my red onions, with some plants out of a group of 4 failing a bit like the shallots.
So far White onions and garlic look to be unaffected.
Im now thinking it might be white onion Rot ( arrrrrrrrrrrrrrggggHH!)
but when ive looked at the bulbs ther are no tiny black spores or signs of the white fluffy fungus ive seen in pics off the interweb.
So could it be just a damp spring? and deep planting . Its a new garden that im just getting to know, and my next door neighbours shallots onion crop looks okay.
Has anyone had white onion rot locally not sure if its about here, i seem to remenber that Dick turvey might have had it at his place?
Either its always been in my soil or perhaps come in from an outside source.
If it is then i wont be growing them any more as I hear it 20 years + to let it die out. and have to put the place on lock down :(
any help or advice Appreciated!!
allium rot
Hi Neil,
What you describe seems to be a fairly common problem here in Otago... it does sound like a fungal rot to me, I have always known it as 'fusarium' but like you mention, that is almost always accompanied by an obvious white mould on the underground parts of the plant or at least an obvious rotted appearance (sometimes the fungus itself begins to rot under damp conditions). I have never noticed black dots though even when obvious fungal rot is present. It doesn't seem to hit garlic until later in the season, even around harvest time. So in January or so, keep a close eye on your garlic patch, even give some plants a gentle tug to make sure they still have roots. If the rot begins to set in it can be worth harvesting slightly early to save the rest of your crop even if it's not 100% ripe for the picking.
Other than that I don't know much about this. I have had onions, garlic and leeks affected by it before. I believe it was brought in to my garden on swapped garlic cloves. I kept going with my normal crop rotation and lo and behold, once I re-planted alliums in the same patch about 3 years later, the rot was still present. So yes it does seem to take a long time to clear out of the soil, I am not sure if there is anything that you can do to hasten the process.
There is one trick I know of which applies to land affeted with club root which hinders the growth of brassicas. Basically it works on the premise that the spores of the fungus lay dormant in the soil until such a time that they find an appropriate host - in this case broccoli, cabbages etc. What you can do is get a whole heap of brassica leaves and plant matter, pulverise the crap out of it or even better blend it up somehow, then mix with water and strain through a sieve or muslin cloth to remove any actual plant matter. Thouroughly drench the affected area with this solution (keeping in mind it needs to penetrate deeply). Apparently, the spores get all excited recognising the presence of brassica juices, and the spores germinate. But since there are no actual brassica plants there, they cannot keep going and continue to the next generation. I have known this method to work for club root after 3-4 applications. Maybe you could try something similar with your alliums (of course using allium plant matter in place of brassica) and see what happens?
Also, since its newly broken in ground perhaps it is a bit acidic - not sure if you added lime or not already but if not, try adding some crushed limestone before your next crop of veges.
planting depth
Also, for the record with regards to planting depth, I have noticed from trial and error that both onions and shallots seem to do best if they're mostly above ground. Like you mentioned here in Otago we can get some pretty damp springs and summers and these plants are more fans of dry conditions. For both onions and shallots I aim to have the widest part of the bulb at soil level. Garlic seems to do good with the bulb 100% underground, but they are definitely vulnerable to fungus.
Hey thanks for the info
Hey thanks for the info Bart. The juice application sounds like a novel approach. Id probably let it run through this year and then random plant areas in beds next year to s try and see where it has spread to.
I limed before putting my alliums in.
removing some top soil now around the shallots.
Its initially appeared on the red onions which are in an area on their own. I planted them in groups of 4 onions as an experiment , and in some groups a couple of plants have failed.
The White groups of 4 seem okay and Ive got white singles in another part of the garden.
Ive got about 80 garlic bulbs in . fingers crossed but It could be a Disaster if i start to see these falling over as well.
Thinking about it. when I grew the white onion seedlings from seed in the autumn, some fell over then so i wonder if that was the start of it? that was some thing that spread and rotted the rots away. It was only a few plants and so I ignored it just thinking it was small thing.. But that was in the whites , which seem to be unaffected now. Hmmm more study I think!