Good to see a HKer maintain their garden as proper garden and not like those who paved up every square inches of the outdoor spaces , front & back and block out every possibility of life. It’s blasphemy. Though i would suggest eradicate pest using organic methods. Plenty ideas online. This way you won’t harm the good pollinators, especially bees. As a keen gardener , I’m sure you are aware bees of every kind are on decline and us human were the one who destroy them. So we must now protect them as much as possible. Happy gardening. 🧑🌾