Stem plants are the fast growers of the planted tank. Ludwigia, Rotala, Bacopa, Hygrophila, Limnophila and Cabomba all grow upward, soak up nutrients from the water, and help keep algae in check once they get going. You trim the tops, replant them, and one bunch turns into a full background in a few months. Reds like Rotala and dark Ludwigia color up best with strong light, and CO2 helps a lot. Greens like Hygrophila and Bacopa are more forgiving. Some listings are sold by the bunch and others by the single stem, so check each one. Everything we sell is grown fully submerged, or labeled emersed.