Onions
There is no real archaeological evidence of onions so the domestication of them as a garden vegetable is really guesswork. Some people believe they were first domesticated in Iran and Palestine but others suggest central Asia. They are known to have been grown in Egypt 3500 years ago as they were left in tombs dating back that far. Other evidence shows the Sumerians grew them and the Romans introduced them to Egypt while archaeologists have found evidence of a field of them in Pompeii.
Onions however have not changed much in shape or colour. Recent breeding programmes have introduced pest and disease resistant strains, extended their hardiness range and reducing the taste to the new and more popular sweeter onions.
Globe onions, Allium cepa, is one of about 300 species with about 70 species cultivated in different parts of the world. However the Globe onion Allium cepa is the most commonly grown as a vegetable as it has the widest range of uses because of its flavour, being hot, mouth watering, savoury and pungent.
Growing onions is quite easy. The soil needs to be well drained with some organic matter but not overly rich and very well drained If it is too rich there will be a lot of top growth and the bulb will be small. Sown after another crop of leafy vegetables would be good. Prepare the soil well with some deeper cultivation with a fork to make sure the ground is soft.
Sow the onion seeds thinly along a prepared row. Too many seeds will give a crowded crop which will need a lot of thinning. Some people plant in single wide spaced rows but several closer rows creating a bed of onions is fine and uses less land. Once growing, and about 5 cm high, thinning can be done to about 100mm apart. If needed, the thinnings can be transplanted into another row with out affecting their growth or could be used in salads similar to chives.
Onion seed can be sown at two times a year as it is a very hardy plant. In early spring July or August often leads to rapid growth of onions however this can be tricky in colder areas. Sowing seeds in autumn and having them germinated and growing slowly through the winter is a good alternative. For those wanting spring plantings another option is to purchase onion seedlings and plant them out in spring to save several weeks waiting for the seeds to germinate. The earlier they are planted the longer growing period they will have.
During their growing season the only pests are thrips, and the diseases are mildew and botrytis.
Onions stop growing on the longest day which is about 22 December each year. Their inbuilt biological clock, based on hours of daylight tells them to stop growing. That is why we need the longest growing time to get big onions.
If small onions are required then harvest them early. However as they finish growing at Christmas they can be lifted and left on the ground to dry out. The tops can be bent over if desirable. Once dry the tops can be removed or used to tie the onions up for hanging in a dry airy shed.
There are a number of varieties to choose from. Early Californian Red and Ailsa Craig. Main crop varieties are Pukekohe Longkeeper, M&R Early, Longkeeper and Brown Spanish. Spring onion varieties are Evergreen branching and White Lisbon.
Onions however have not changed much in shape or colour. Recent breeding programmes have introduced pest and disease resistant strains, extended their hardiness range and reducing the taste to the new and more popular sweeter onions.
Globe onions, Allium cepa, is one of about 300 species with about 70 species cultivated in different parts of the world. However the Globe onion Allium cepa is the most commonly grown as a vegetable as it has the widest range of uses because of its flavour, being hot, mouth watering, savoury and pungent.
Growing onions is quite easy. The soil needs to be well drained with some organic matter but not overly rich and very well drained If it is too rich there will be a lot of top growth and the bulb will be small. Sown after another crop of leafy vegetables would be good. Prepare the soil well with some deeper cultivation with a fork to make sure the ground is soft.
Sow the onion seeds thinly along a prepared row. Too many seeds will give a crowded crop which will need a lot of thinning. Some people plant in single wide spaced rows but several closer rows creating a bed of onions is fine and uses less land. Once growing, and about 5 cm high, thinning can be done to about 100mm apart. If needed, the thinnings can be transplanted into another row with out affecting their growth or could be used in salads similar to chives.
Onion seed can be sown at two times a year as it is a very hardy plant. In early spring July or August often leads to rapid growth of onions however this can be tricky in colder areas. Sowing seeds in autumn and having them germinated and growing slowly through the winter is a good alternative. For those wanting spring plantings another option is to purchase onion seedlings and plant them out in spring to save several weeks waiting for the seeds to germinate. The earlier they are planted the longer growing period they will have.
During their growing season the only pests are thrips, and the diseases are mildew and botrytis.
Onions stop growing on the longest day which is about 22 December each year. Their inbuilt biological clock, based on hours of daylight tells them to stop growing. That is why we need the longest growing time to get big onions.
If small onions are required then harvest them early. However as they finish growing at Christmas they can be lifted and left on the ground to dry out. The tops can be bent over if desirable. Once dry the tops can be removed or used to tie the onions up for hanging in a dry airy shed.
There are a number of varieties to choose from. Early Californian Red and Ailsa Craig. Main crop varieties are Pukekohe Longkeeper, M&R Early, Longkeeper and Brown Spanish. Spring onion varieties are Evergreen branching and White Lisbon.