I am a typical gardener, who likes to grow many plant species, if possible. I have more than a hundred and fifty pots inside my home and most of them are in my conservatory. As you may imagine, they are a bit crowded, so they can all receive some light - some more, some less, considering their needs. In the spring, I always carry about a third of the pots outside and then carry them back inside in the fall. Those are the hibiscuses, the citrus trees, the impatiens, the geraniums, the lilies, the aloes, the oleanders, the euphorbias and the oxalis.
Before bringing them back inside, I usually clean all the pots and spray the plants with the hose and I also spray them for bugs. Yet, somehow I must have brought some whiteflies inside, most probably on the poinsettias. How did they get there and why didn't they die after I sprayed with the bug spray, I couldn't understand. It was a bad idea to take the poinsettias outside anyway, because they weren't doing well during the hot summer days, moreover they always had whiteflies on them, which I had to fight (spray) several times during the winter. Some of them would die, but some would still survive, because they have this ability to fly all over and land on the window or on other plants. They mostly preferred the kalanchoes, some of which they almost destroyed, until I became aware of what was happening and started to spray constantly. I have a bug spray I use for the mealy bugs and mites on the citrus and lilies, which works very well, but not so well on the whiteflies. These bad minuscule bugs are so small that one can barely see them but they are small white flies. However, as small as they are, they do lots of damage to the plants by sucking their sap.
I couldn't spray with a stronger bug spray, which has a bad odour and not good for the humans. A specialist recommended it to me, yet he mentioned that I should take the plants outside for spraying. That wasn't a good idea during winter - moreover, some of the whiteflies would still remain inside the conservatory.

Basil bush blooming in my garden
I kept on spraying with the normal bug spray I had and managed to keep the whiteflies under control, yet they were still there up until last fall, when a huge light bulb turned on above my head (that means that I found the way to get rid of them!).
I'm always growing basil in my garden because I like pesto and I prefer to make it with my own plants. After ripping off the leaves for the pesto, I let the basil plants dry off, all tied up in bunches. Someone told me to keep the dry basil in the shed, to keep the mice away, as they seem to hate the basil scent. I also know that basil repels some pests, including mosquitoes and flies, which is also a reason why I'm growing it around the house. The bad whiteflies are also giving me headaches in the vegetable garden, when they are all over the radishes, the sweet peas, cabbage and even on the tomato plants. It's true that I can spray with a stronger insecticide and kill some of them - yet I need to take care of the bees and not to spray on the flowers. Be as it may, do you think that all the whiteflies would die after spraying? No, because they fly away to other plants, which are growing next to my garden and then come back again, after the insecticide's effect is over. That's why I prefer to grow basil next to the vegetables and keep the whiteflies and even other pests away.

Green and red basil next to the cabbage patch in my garden

Last fall, after picking the basil I needed for the pesto, I still had two smaller basil plants in the garden, which I thought I'd better save and keep indoors during the winter, so I can use fresh basil leaves for my meals. It's better than buying a whole plant from the store! I dug out the plants and put them each in a pot, then brought them to my conservatory. And then it came to me! Why not using the basil plants as a repellent for the whiteflies? If they can repel flies, maybe they can repel whiteflies too - possibly, the mealy bugs also. That's why I put the basil pots next to the poinsettias, kallanchoe and lilies. Mealy bugs were bothered by the basil's scent and they seemed to shrink and even run away from it. Those bugs are really hard to get rid of, so even that was a success. After a while, I checked for the white flies, which were everywhere before, but there weren't any alive. Basil must have been bad for them. I'm not sure what happened, whether they flew away or died - or flew away and died? Anyway, I'm happy to have gotten rid of them. From now on, basil has a reserved spot in my conservatory.