Growing onion sets & seeds for the year - Allotment 2016 day 3
Growing onion sets and seeds is a lot more complex and interesting than I ever imagined it would be. Onions take a long time to grow and they are one of the first crops to get started each year.
Germinating onion seeds
The traditional date for starting off onion seeds is either Boxing Day or New Year's day. These would be for onions that would then be lifted and dried at the end of Summer and beginning of Autumn. The problem in the UK is that this really isn't the best time for anything to grow as there is very little light during the day. The Sun has just passed through its lowest point of the year and even though each day will see it rise a little higher and shine for a little longer, this isn't really enough. The day will start at 8:00am and finish around 4:00pm and the further North you go the shorter the day gets. That makes germinating onion seeds difficult. That is why I used grow lights and a grow tent this year.
What are onion sets?
If you don't have a grow tent, then onion sets are a great alternative. An onion set is a one year old onion seed that has grown under natural light for a summer season. It forms a small bulb, and has gone through its first long growing spurt but hasn't yet formed an onion. Therefore they don't need to be planted in the middle of winter. As days get steadily longer into February, onion sets can be planted to produce an early crop in Summer. Onion sets are therefore a lot easier and a lot quicker to grow than onion seeds.
Growing onion sets does have some drawbacks
Onion sets are almost a year old when you plant them and have already seen a Winter. Onions form a bulb in their first full year of growth and then form a seed head in their second year. The problem with onion sets is that they have already seen a Summer and a Winter. If you plant them in Spring that first turns hot and then cold again, the onion tricks itself into thinking that this is its second year and so it begins to form a seed head. The energy to form the seed head comes from the centre of the onion bulb, which is the bit we want to eat. Once the seed head has formed the centre of the onion starts to rot and so it won't grow any bigger or store for very long.
Growing onion sets and seeds together
What I am trying to do by growing both seeds and sets is to get two crops for the year. The first to mature will be the sets and I expect them to come through between June and July depending on the weather. Then towards the end of the season in August I will expect to see my onions grown from seed mature. By then we will already be eating the onion sets and so the new set will see us through the Winter and Spring until we have another crop next year.
Which varieties are you growing?
This year I am growing onion sets called Stuttgarter Giant. They grow quite large quite quickly and also have a really nice flavour. They can be quite a strong onion, but any onion you grow yourself will have a stronger taste than anything you can buy in the shops.
My onions grown from seed are all a variety called Kelsae. Kelsae onions grow very large and are used as a Show variety as they have a very attractive pale colouring, regular and regular shape. Unlike a lot of show variety vegetables, Kelsae onions also have a wonderful quite mild flavour that is perfect for cooking.
Between the two of them I hope to have some spectacular onions this year. This video shows me starting the onion sets off and checking the progress of my onion seeds as well as looking at my other seeds for the year.
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