A weed is anything growing where you don't want it to. Leave everthing in the garden until mid summer at the earlist and if you see something you don't like pull it out. Most people class things like dandilions as weeds but some people like them and encourage then to grow the same can be said about daisys growing in lawns some people like the look of them and leave them to grow, others hate them.
Gaz the garden doctor, February 2010