Even in the safety of your own home plants are still susceptible to an attack from a number of pests and disease. Basil in particular can be difficult herb to grow as issues of going to seed, overwatering and attacks by aphid can be common and deadly.
Aphids are recognisable on plants as tiny white specks, often found on the underside of leaves. They can appear overnight and if not treated can quickly spread and lead to an infestation of your crop. Aphids attack plants such as basil by living on the leaves and sucking the plants sap. This will overtime weaken the plant eventually killing it. The leaves most susceptible to attack are youngest and freshest and most succulent leaves. If you want to treat your basil plants for aphids it is important to pay particular attention to these areas.
To treat plants that you hope to eat for pest problems the number of options available to you are limited. There are a number of insecticides and pest control options that kill aphids but they are not something that you would want to eat with your basil. So with that in mind what options are available? Well aphids are in general easy to kill, the problem with aphids only occurs when an infestation occurs. To kill off large number of these bugs repeated and regular treatment over a number of weeks is required.
One way that you can get rid of your aphid problem is to spray them with a powerful water sprayer such as a pressure water sprayer. This will knock the aphids off the plant and drown them. However this will only kill less than half and repeated application is required.
A more delicate and accurate method that I use is to apply a water and washing up liquid mix to the leaves and affected areas of the plants. A cup of water and small squirt of washing up liquid works well, this should then be applied to the plant using a small painting bush. The smaller the bush the easier it is the get to those hard to reach parts of the basil plant – which generally has the most insects. This method kills the majority of insects but 4 applications over 2 weeks is still recommended. All indoor plants and herbs should be treated at the same time and those that have a severe infestation should be isolated from the healthy plants to prevent the problem spreading.
Generally if one herb or Basil plant is infested then it is most likely that all the others are too. Once the problem has passed you should stay vigilant as it only takes a few surviving aphids to start another infestation some weeks later.