With one billion households on the planet, and greed the dominant world religion we desperately need weedy gardeners. Now there is a plant you may have heard about - Ageratum conyzoides - the Billy Goat Weed. Moist grassland and woodland edge in hilly areas of the Neotropics used to be his only home. Yet someone, sometime past brought hairy Ageratum east, deliberately or unwittingly, with food crops to Africa (and many place besides) so that nowadays this cute yet highly pungent blue or mauve or pinkish white pom-pom flowered Aster is an alien par excellence and currently dominates my day .. Outdoors. Indoors, as now, my life is dominated by the mercurial magic of another alien in Africa - electricity! Something strange and new that is colonising this continent somewhat less effectively than bad old Billy Goat Weed.