Growing Colourful Onions
Onions are a hugely useful vegetable that is good for making sauces, is delicious in stews and soups, and beautifully tangy in salads, and is guaranteed to a zing to the plainest sandwiches.
But not all onions are created equal. They come in different colours (primarily red, white, yellow and brown) and sizes, and the flavour of different types really is different.
Different coloured onions: Caledon Globe, White Pearl and Red Creole.
Different Types of Onions
Most of the onions on our supermarket and veggie store shelves are round bulbing onions. There are various cultivars including:
- Texas Grano, an early to mid-season type that is known to be a heavy yielder.
- Australian Brown, an excellent late cultivar that has a distinctive reddish-brown skin (or scales as it is more correctly termed).
- Caledon Globe, which is round in shape with a straw-coloured skin and pale yellow flesh.
- Hojem, a mid-season cultivar that is round and has a darkish skin.
- Various red onions.
One of the major differences between the various types of onions is that they have different needs in terms of the day length required for bulbing. For this reason you will see that some, like Texas Grando, are described as a short day onion, while others, including both the Australian Brown and Caledon Globe cultivars, are described as long day cultivars.
In all cultivars, bulbing will be accelerated if the temperature increases. Temperatures extremes also affect the shape of the bulb.
Spring onions, which are also called green onions, Japanese bunching onions and nebuka, have small white swollen bulbs (although they are technically not bulbing onions), long slender white stems and distinctive green tops (which are in fact hollow leaves). In fact spring onions are not a separate cultivar, but rather the seedling stage of a variety of cultivars, including White Lisbon, White Welsh and White Pearl onions. Even if these are packaged as “spring onions”, they may be grown to maturity, as bulb onions.
Used fresh or cooked, spring onions are essential to Japanese, Chinese and Thai cooking. They are also commonly used raw and finely chopped as a garnish for many other dishes including stews, soups and stir fries.
Compare the Taste of Different Onions
Not only do they look different, but different types of onions also have different tastes.
Compare the light burn of a newly picked spring onion to a large yellow onion for starters. Then slice open a pretty red onion and you’ll notice a sweetness the other two lack. That is why red onions are so often preferred for salad dishes.
You will also find that if you lightly blanch onions, by popping them into boiling water for a minute or two, you will lessen the bite.
Grow Onions at Home
Bulbing onions grow well in most soil types, except for heavy clay. Most cultivars need lots of moisture and they grow best in cool conditions, especially during the first few months.
If you want a good yield of firm onions, you will find that sowing time is more critical with bulbing onions than with most other vegetables, including tomatoes and potatoes. You also need to be aware of the fact that onions have a fairly long growing season, and they need constant attention during this time to ensure that they remain well nourished and watered, and are not threatened by pests or disease.
During the growth period, it is also important to weed regularly. Once the bulbs are well formed, you can reduce the amount of water given, so that the bulbs have a chance to firm up and dry out.
Annette Welsford has a partial degree in Horticulture and a Post Graduate Certificate in marketing. Having lived in the cold, temperate and hot parts of Australia and the UK, she has gained experience over the years with gardening in a variety of climates. Annette also worked for a fertilizer company where she was responsible for developing, editing and publishing a range of technical manuals on nutrition and fungal diseases for a wide range of horticultural crops including tomatoes. Annette is Managing Director of Commonsense Marketing Pty Ltd, a publishing and marketing company, responsible for the editing, design and worldwide marketing of the How to Grow books, and other products. Commonsense Marketing also provides expert offline and online marketing consulting and design services to a variety of small to medium sized businesses.
