Garden Action

The premier gardening information source

Plant and Sow Onion Seed and Sets (continued page 2)

How To Plant/Sow Onion Seed and Sets

Sowing Maincrop Onion Seed

Choose a dry day to sow onion seed, March is ideal in your area. The soil should be moist but not wet, if it sticks to your boots, wait a day or so until conditions are dryer.  Dig out drills (see diagram) about 2cm (3/4 inch) deep and 30cm (1foot) apart. Sow the onion seed as thinly as possible, three or four seeds every 15cm (6 inch) (right hand row of diagram) gently replacing the soil over the seeds.

Diagram of onion seed drillIt is possible to sow the seeds in a continuous row as shown in the left hand row of the diagram, although more seeds will be required thinning out later will take longer. The seedlings should appear about 20 days later. Onion seed can be sown about 3 weeks earlier if they have the protection of poly tunnels - click here for more details of how to use poly tunnels. Click here to buy a poly-tunnel or cloche online from our recommended suppliers.

Sowing Maincrop Onion Sets
Picture of onion setsOnion sets provide an easier method of growing onions and with more chance of success. The picture on the right shows the size of the small onion sets in comparison to the fully grown onion.

Plant onion sets 10cm (4inch) apart in rows 30cm (1 foot) apart to a depth where only the very tips of the sets are just showing through the soil. Dig a hole in the soil with a trowel and place them in the hole with their necks uppermost. Do not just push them into the soil, they may grow out of the soil later.

Sowing Spring (Salad) Onions
Sow them in drills in a continuous row lightly covering the seed with soil. Sow at three weekly intervals from March to June to ensure a continuous supply.

Sowing Japanese Onion Seeds
Japanese onions are sown in mid August in exactly the same manner as maincrop onion seeds.




Name: d. mansbridge
Date posted: July 18, 2011 - 03:05 am
Message: For the first time my onions have started to bolt we hve had in my area a very dry 3 months I have watered very well but today is more like winter than summer and I noticed a doz. of 150 sets I planted are going to seed what should I do leave them until Sept or take up the ones that have bolted now? Thaks for any advice Dave M

Name: jim
Date posted: June 05, 2011 - 11:16 am
Message: my onions dont seem to swell up got plenty of green but no sign of bulb getting bigger