Alkanet, the little white spots on the leaves give it away – it has an effective blue flower and is used as a border plant but self seeds like mad and I am not that fond of it. If you like it just make sure you dead head it before it goes to seed! The humble nettle! Cleaver, the dogs bring endless burrs into the garden, but they are easy enough to pull up if you get ’em young A baby dock, with a mega tap root h
Weedling or Seedling? Below are seedlings in my book, which means that they are thugs if left to their own devices… Creeping buttercup, Ranunculus repens Arum Lily, Lords and Ladies, white flower followed by (poisonous) red berries, a prolific self seeder. Arum Celandine, a pretty yellow flower but better in a woodland setting than in the borders, make sure you get the tiny bulbils or it will be back!