Oh I didn't see this one before. I'm up in Norjylland so a similar climate but the 10th may for summer plants sounds very early, here they don't go out before 1st June. I do onions here and at work, at work we have thin sandy soil and I have a silty soil (old lake bed) my soil doesn't drain, if I dig a hole to check drainage it fills up as the watertable is so high. But at work and at home I manage to grow carrots and onions perfectly sucessfully. HOWEVER this year neither of our onions did very well, I mean I got a crop and some were nice and large but the average was poor.
I buy seed which I start in Feburary and then plant out in March/April when the soil begins to dry enough Onion sets also go out at the same time, onions do not mind a bit of frost. Cabbages yes large and cabbage whites will eat the crop, you can spray there are two organic pesticides you can use in Denmark, at work we used Bacillus thuringiensis it does work very well. Other than that if you only have a few plants and lots of time you could hand pick, or use netting.
Carrots. They do fine even in my damp waterlogged soil, they do only grow down to the watertable to around 15cm in my case but that is good enough. Carrot fly is the only issue we have had and it has never been at a bad level. there is a website that tells you when carrot flies have been sighted, I unfortunatly cannot remember the URL
And back to the original post, no you can't leave them for another year, infact if they are showing green again you have probably left them too long, mine were out of the ground late september, they will rot if left much later in our soggy climate.
One last thing, onions HATE weeds. so make sure you get rid of them
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Oh I didn't see this one before. I'm up in Norjylland so a similar climate but the 10th may for summer plants sounds very early, here they don't go out before 1st June. I do onions here and at work, at work we have thin sandy soil and I have a silty soil (old lake bed) my soil doesn't drain, if I dig a hole to check drainage it fills up as the watertable is so high. But at work and at home I manage to grow carrots and onions perfectly sucessfully. HOWEVER this year neither of our onions did very well, I mean I got a crop and some were nice and large but the average was poor.
I buy seed which I start in Feburary and then plant out in March/April when the soil begins to dry enough Onion sets also go out at the same time, onions do not mind a bit of frost. Cabbages yes large and cabbage whites will eat the crop, you can spray there are two organic pesticides you can use in Denmark, at work we used Bacillus thuringiensis it does work very well. Other than that if you only have a few plants and lots of time you could hand pick, or use netting.
Carrots. They do fine even in my damp waterlogged soil, they do only grow down to the watertable to around 15cm in my case but that is good enough. Carrot fly is the only issue we have had and it has never been at a bad level. there is a website that tells you when carrot flies have been sighted, I unfortunatly cannot remember the URL
And back to the original post, no you can't leave them for another year, infact if they are showing green again you have probably left them too long, mine were out of the ground late september, they will rot if left much later in our soggy climate.
One last thing, onions HATE weeds. so make sure you get rid of them
Last edited: 08 November 2017 15:42:13