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Onion sets

A friend has just given me half of her onion sets so that's 35 onion's. I don't know what to do with them as never grown onions before. Do you treat them like a seed and put them into small pots or do they have to go into the ground as they are. Our garden is on clay and water logged, drainage is very bad although I have been pilling lots of the good stuff on it and then covered it with cardboard which is now breaking down. I grew leeks last year and they got going well but once I planted them out they rotted in the wet ground. Also how long from planting till I can use them in the kitchen.


  • cornellycornelly Posts: 932
    I plant onion sets pushed into the soil, as they would be when planted in the garden, in small pots, in a cold glasshouse, using a mixture of garden soil and leaf mold, until planted out late April, our soil is heavy clay and there is a tendency to rot if placed strait into the garden as new sets.
  • Thanks cornelly, as I said not grown them before and didn't get the info that came with them they were just in a plastic bag from a friend. When I plant them out would you say around 10 inches apart? How long do they take to get to a size that can be used. Thanks again.
  • BobTheGardenerBobTheGardener Leicestershire, UKPosts: 10,088
    I also start them off in the GH but in modules and plant out once roots have formed.  4 inches between each one in the row works for me, with rows about a foot apart.  You can start harvesting them when they are a useful size (eg egg or larger) which will be roughly from the beginning of July but I grow for storage so wait until the tops flop over and start turning brown, at which point they are lifted and left on the soil until the roots dry out.
    A trowel in the hand is worth a thousand lost under a bush.
  • Thanks for that BobTheGardener. I don't have a very big veg garden so if they can be planted out four inches apart I should manage to get them all in. Do they need to be fed if so what would you suggest. I really can't wait for the warmer weather to arrive. I was outside making a sort of planting ruler with a piece of 6 ft by 1 x 1 inch wood this afternoon.
  • BobTheGardenerBobTheGardener Leicestershire, UKPosts: 10,088
    I generally sprinkle fish, blood & bone over the area (used as per pack instructions) and rake that in before planting. Onions are quite greedy but the FB&B provides nutrients over a long enough period to keep them happy.  My veg plot also gets a mulch of well-rotted manure each autumn which helps.
    A trowel in the hand is worth a thousand lost under a bush.
  • Thanks again  BobTheGardener re the BFB. I have put manure down which I have had in the garden for almost a year along with compost which was made last year That all went down around November as someone said I should sort the soil out before I start planting. I covered it all with cardboard box's which have all started to fall apart. The compost and manure would have been about 4 inches or there about's. Lifted some today and found some worms which is good. I am really looking forward to seeing what I can grow for us to eat this year.
  • KT53KT53 Posts: 4,706
    4" apart is a bit close for my liking, particularly if you have plenty of space.  I like to leave enough space to get a hoe between them for weeding, so about 6" apart and 12" between rows.
  • Thanks KT53, I can see by putting them to close I wouldn't get a hoe in-between. I don't have a very big veg plot ruffly 8 ft by 20 ft but would like to grow Runner beans up a wigwam, Peas, Carrots, Onions and then some salad in the small bed by the house. I have bought some fleece and cains to make a screen round the carrots as I understand they can get carrot fly but the fly only fly's 18 inches from the ground so I'll make the screen about 2 ft high. If I get on OK this year I want to take some of the lawn and make the veg patch bigger.
  • SkandiSkandi Northern DenmarkPosts: 1,005
    edited February 2019
    I plant my sets direct last year that was the 24th of April, you don't want sets to get too cold or they are more likely to bolt (saying that my sets had a 10% bolt rate last year whereas the ones from seed had about 2%)
    You can also plant them in 3's put each cluster around 6 inches apart. Or measure your hoe blade! I find I cannot really hoe round them but hand weeding doesn't take long. I personally plant them in clumps of 4 or 5 and thin them out as large fresh green onions. leaving three to mature in each spot, you can just about see what I am talking about in this photo, this was taken during the drought we had last year. I managed to dry those on the right in the sun (from sets) but the ones on the left (from seed not sets) were a week too late being ready and got seriously rained on!
    As to carrot fly, my carrots are just visible on the left, I always plant them next to my onions as I have heard the scent confuses the flies, it seems to work for me but I haven't tried a control without onions.
  • Morning Skandi, Thank you for the advice. You did really well with your onions last year I hope mine will be as good. Didn't think of onion near the carrots, might put a few rows of carrots then onions and so on. I'm going out in a bit to get some lettuce and beetroot and I will also be looking for a veg gardening book along with something to keep the advice people on here have been kind enough to give me. Am I right that bolting is when they go to seed? You look to have a good size garden I wish I did.
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