A few years ago I tried an interesting method I read about in a gardening magazine and it proved to be very effective in controlling the onion fly. It turns out that these pests do not tolerate the smell of mowing grass, so this method is ideal for gardeners who stick to natural fertilizers.
I used this method and the onion fly practically disappeared on its own, without the need for any chemical treatment. The smell of cut grass stays in the air for quite a while, between 5 and 7 days, after which it is advisable to renew it. In addition, a mown grass bed helps to retain moisture in the soil and prevents crusting after watering.
How do you know if an onion fly has laid eggs on an onion? Usually, this can be seen with the naked eye. Feather. The bulbs begin to turn yellow and gradually fade. A clear sign of the presence of an onion fly is a strong yellowing of the tips of the feathers, which can occur after just a few days. I have also tried several commercial products and liked a product called Zemlin.
The pellets are simply spread evenly over the garden bed, or they can be dissolved in water and watered with onions, but this should be done no later than 40 days before harvest. The year I used Zemlin to water the onion bed, there were no onion flies.
Another way to combat the pest is to water the onion bed with a soda solution. This treatment can replace tobacco, pepper and even the well-known saline solution. As for water, dissolve 2 tablespoons of baking soda in 10 liters of water. Do not carry out more than two waterings per season.
