It hasn’t been a bad year for the onions – so far. Although wet and cool to start with the recent warmth and sun has seen a burst of growth and I have reasonable hopes for them. I have grown four types: three from seed and one from sets.

I planted ‘Karmen’ sets in March. ‘Karmen’ is a red onion that can also be grown from seed.

March-planted red onion sets (‘Karmen’) have done well

I like red onions and they are worth growing yourself because they are relatively expensive to buy compared to white onions. But they are more prone to bolting (sending up a flower scape). This seems to be a common problem among all onion sets but especially the red onions. A few more are sending up flower stems every day and I would say that 20% have bolted. The problem with this is that when they do this the bulb stops growing and the bulbs will have a hard stem in the centre. They do not store well and although parts of the bulb are edible they are not so good.

… but about twenty of the 100 have bolted.

Even so, a good number have potential.

In contrast to these mediocre results, the autumn-planted ‘Senshyu’  onions have been a great success – so far. They coped well with the wet winter and burst into growth in April and many are near-ready for harvest, a good month before spring-sown or spring-planted onions will be ready. The bulbs are not huge but they are definitely worth growing.

The autumn-planted ‘Senshyu’ onions have done well

The ‘Mammoth’ onions are causing me concern though. Onion bulbs are made of the base of the leaves so the more leaves an onion has, the bigger the bulbs will be. Onions stop producing new leaves after midsummer’s day when the day length starts to reduce. So I only have a few more days for these onions to make new leaves. After that time the leaf growth stops and the bulbs start to enlarge. Despite giving these onions an early start and good average growing conditions they have not got the big tops I was hoping for so I think the onions will be a bit average. I spaced them at 30-45cm apart in the rows, varying it to see if it made much difference – I don’t think it will!

The Robinsons ‘Mammoth’ onions have some growing to do to live up to their name!

Last year I grew ‘Florence Red’ from seed and it did well, making lots of long ‘torpedo’ bulbs of varying shades of red. I repeated it this year, sowing several seeds per cell in cell trays in March and planting them out in April. They have done well but a lot have been pulled for eating as immature onions. That is the point of growing them this way. The immature onions are pulled from the clumps to leave just one to mature but the demand for scallions is such that not a lot will be left to mature. Note in the photo that the ‘strain’ is not very ‘pure’ and the colour of the onions varies considerably.

‘Florence Red’ made good onions last year but a lot are disappearing – pulled as scallions (spring onions)

autumn-planted onions, how to grow onions, onion bolting, onion florence red, onion karmen, onion robinsons mammoth, onion senshyu, onion sets