Onion Sets in Module Trays

onion sets planted early

I usually plant my onion sets straight into the ground in spring, covering with a mesh frame to keep the birds off until they’ve sprouted and developed a good root system to anchor them in. I harvest a decent crop but I do get a number of smallish bulbs despite my soil being well nourished.

onions drying

Red onions drying

Today I planted half my onion sets in module trays filled with compost (‘Red Baron’ and ‘Stuttgarter Giant’), growing them on in my unheated greenhouse. The other half will be planted out into the ground, in the usual way. The idea is to give half the sets a bit of a head start, an experiment really.

onion sets planted in module trays

onion sets in module trays

I’m curious to see if this makes any difference to the overall size of bulbs come harvest time, compared to the sets planted straight into the ground a month or so later.


I’ll let you know how I get on.

13 thoughts on “Onion Sets in Module Trays

  1. This year we are going to try the opposite. Last year we started quite a few things ahead of time and compared them to what we later planted straight in the ground. It seems the transplanting set the starts back enough that the directly planted seeds caught up and some plants surpassed the transplants. So this year we are going to experiment with some earlier in the ground under cover (probably hoops). Looking forward to seeing what results you find.


  2. I simply don’t have room to start off them like that so sow mine direct. I’m growing red Baron for the first time so it’ll be interesting to see how we both get on with them. xx


  3. I’ve seen quite a few people do that this year, sadly I just dont have the space to seperate my onions, so the sets are already in the ground (have been since Nov last year) and are doing well. I am also growing from seed this year so they are in the conservatory. I will be watching to see how they do and might try this next year (if we have space!)



  4. It will be interesting to see how this works out. I had a wide range of sizes in my seed-started onions last year and then this winter I read that spacing affects size. I tend to crowd things so that may have been it, but on the other hand I did get quite a few larger bulbs.


  5. Tempted to follow suit and try in our unheated greenhouse. I always grow stupid amounts of onions anyway and find a varying amount bolt far too easily. This might hold the key to stopping that at least.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.