Although it looks and tastes a bit like oregano, marjoram surprises with its sweetness and its hints of citrus and pine. That brightness might be why the Greeks and Romans considered this Mediterranean perennial a symbol of happiness. You might know it from its starring roles in herbes de Provence and za'atar. A bit more delicate than other perennials, it should be started indoors 8 weeks before last frost and given plenty of sunshine and moderate water.