A plant is herbaceous when its stems stay soft, like a flower, a tomato, or a clump of mint, rather than growing hard and woody like a tree or a shrub. The top of many herbaceous plants dies back in winter, and new stems grow from the roots in spring — though actually, in a warm place some herbaceous plants stay green all year; the point is the stem is not wood, not that the plant must vanish in the cold. Gardeners use this word a lot. A “herbaceous border” is a flower bed full of these soft-stemmed plants, not a row of bushes. It is a garden-and-science word, not a café word. Students often hear herb inside it and think it means “good for cooking or tea.” That is close in origin — Latin herbāceus meant “grassy” — but in plant talk it is about the stem, not about flavour. A rosemary bush is a cooking herb, yet its stems go woody, so a gardener would not call the bush herbaceous.