Hardiness zones 5 - 11
H. cordata, also called lizard's tail, though it is not clear why - probably for how the stems look when leafless- is one tough plant. In the right location (moist soil, sun or shade) it can be quite invasive. For this reason I use it in really difficult sites that are not moist where little else will thrive. In such sites Houttuynia will grow but not invade. Or, I grow it in the pond in pots. Here we consider this plant as a wetland or bog plant.
H. cordata (and there are several cultivars) is a native of Japan. It grows to about 12" tall or a little less in tight groupings of heart-shaped leaves and spreads by runners. Available varieties are highly ornamental, with yellow, cream and pink to red variegations against a rich green with simple white flowers in early summer and the foliage emits a strong orangey or citrus-like fragrance when brushed or bruised.
It is a margin plant, meaning the roots can be in moist to wet soil all the time but does best when not submerged below the crown (where the stem meets the roots) for too long. To prevent it from taking over it is best to grow Houttuynia in pots to contain the runners. In colder zones (5, 6) it is best to remove from the water and mulch it for the winter months. It is a perennial and will re-emerge in Spring with a fresh bouquet of beautiful foliage.