Bunching onions go by a variety of names. They are often called scallions, Japanese bunching onions, green onions, and Welsh onions. There are some very specific varieties as well. They can be used as ornamental plants and harvested. The tall slender green leaves can be a part of an interesting landscape. They can be planted in the garden and even grown indoors.
Cornell University explains the best soil conditions for growing bunching onions. It should have full sunlight. The ph should be neutral. The soil needs to be well drained and high in organic material. Bunching onions do well in raised beds. This a crop you want to rotate every year. Planting should be done where there have not been any onions grown in the last three years. This can be easily accomplished just by rotating rows in the garden.
Prepare the soil by tilling to a depth of about 8 inches. These onions do not have a very deep root system. Make sure the soil is clean and rocks and debris are removed. Add plenty of compost or other organic materials.
Spacing the seeds depends on big you want your bulbs to get. Most people prefer small tender bulbs. These can be planted when the soil temperature reaches about 50 degrees Fahrenheit. For small bulbs place the seeds over a wide row of 4 to 8 inches. For mature and bigger bulbs plant the seeds 4 inches apart. Seeds should be planted about ¼ inch deep.
Bunching onions take about 7 to 10 days to germinate. It is important to keep them evenly watered during this time. Take care not to wash the soil away, as they are not planted too deep. If the goal is to have soft tender bunching onions they should be ready within 8 to 10 weeks. This means that there can be several crops over a growing season.
Of course, like any other plant there are pests that enjoy the crop. Onion maggots are the problem with bunching onions. They can be prevented by using floating row covers and carefully rotating the crops.
Thrips are also a problem for onions. The only organic way to control these is by using yellow sticky traps.
The two most common diseases that are a problem for batching onions are Botrytis leaf blight and Purple blotch. These occur when plants are over crowded and can not dry quickly after watering. Space is essential so air can circulate. It is also important to keep weeds away from onions if you want to avoid issues.
There are so many ways to use batching onions in cooking it is definitely worth adding them into the garden.