Bonsai Trees have the same pests and diseases to deal with as any other plant. We would like to give some advice in this regard in a series of posts. The first to be aware of is aphids.
These pests, also known as greenfly, are widespread and will attack nearly all plants. They cluster around soft stems, shoots and the undersides of leaves – sucking sap.
This causes mottling, blistering, viruses and the deforming of leaves and new growth. In severe infestation, aphids excrete a sticky substance called honeydew, which attracts ants, weakens plants and makes them more susceptible to mould. There are many species of aphids with a variety of colors.
Natural enemies are Ladybirds. One ladybird can eat up to 400 aphids in a week, making them a valuable asset in the garden.
Many chemical insecticides are effective against aphids, but they also kill their natural enemies.
Using soapy water to spray aphids can be effective. You can also make your own herbal spray by boiling two tablespoons of coriander in 200 ml of water.
Garlic, wormwood and basil boiled in water is another effective spray. Apply herbal sprays at least every second day until the infestation has been cleared.
You can also carefully wipe the leaves with a soft, damp cloth to remove sooty mould.
Outdoor Bonsai can be surrounded by “anti-aphids” herbs. Some herbs offer natural alternatives to chemicals and they are not harmful to the environment.
Aphids stay away from chives, tansy and lavender. Research also shows that they will not prey on plants growing near nasturtiums with orange and yellow flowers.