aphid problem on my orange bush

Question

I have an orange bush which was given to me as a present approx 2 and a half years ago.
every year the plant grows well and produces blossom but I have never had any fruit as yet. I noticed recently that the bush was covered in small brown aphids which leave a sticky substance on the leaves. I have sprayed it with a general bug killer but although they have reduced greatly it hasn’t cleared them and although I have physically removed all I can see, more seem to keep appearing. Is there a special spray that I should use. At the moment, I leave the bush out all summer but bring it in to my conservatory once the frosts start. I tried to leave it out last winter in a sheltered spot with a special plant cover over it but the movement of the cover just seemed to knock most of the leaves off.

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Answer 1

Lack of fruit development, as well as susceptibility to insect pests like aphids, are often related to soil fertility and plant nutrition.

I recommend that in spring you repot it into a larger container with a good potting soil. Use a complete organic fertilizer customized for citrus, spring and fall.

Use a preventive insect pest repellent spray every couple of weeks, rather than waiting for an infestation to develop and then having to control it with harsh chemistry. Neem oil is one option.

https://www.gardeningknowhow.com/edible/fruits/oranges/no-fruit-on-orange-trees.htm