'Give me five' can mean 'wait a few moments for me' ('five minutes' is an idiom meaning 'a short length of time'). It can also mean 'congratulate me'. Colleagues often congratulate each other by...
It means, if you have one, you seem to have the ability to make plantss flourish - you usually have a beautiful garden and a knack of making plants and cuttings and seeds grow. The opposite, is to...