Can you make your own fertiliser from weeds?

Hilary and Sabrina are on the tools this week, answering your garden questions.2:10 The link between army worm grubs and the spate of magpie and crow deaths.14:14 Mary has given her citrus tree every soil amendment available and yet it still complains (citrus leaf miner).16:50 Herb asks if stinky weed tea is as good as manure for fertilising the garden.