Cuphea hyssopifolia aka Mexican Heather

Cuphea hyssopifolia is a small evergreen shrub called Mexican heather or false heather. It belongs to the loosestrife family, not the heather family. Its native range covers Mexico and Central America. It grows near streams and in moist forests. People grow it as an ornamental far beyond its home range. It has spread into the wild in Hawaii and New Zealand. Some sources regard it as invasive in those places.

The shrub forms a dense, rounded mound with many branches. Garden plants reach about 1–2 feet [0.3–0.6 metres] tall. One tropical source reports heights of 2.3 feet [0.7 metres]. Reported spreads range from 0.75–3.3 feet [0.23–1 metre]. Soft, fine hairs cover the green stems. Small, narrow leaves grow in pairs along each stem. Their glossy upper sides are green, while fine hairs cover their undersides. The leaves have smooth edges and give the plant a fine texture. They stay green in warm climates and indoors.

Small lavender flowers open from summer until frost. Each trumpet-shaped bloom has six petals and a green calyx. Flowers grow singly where leaves meet the stems. Bees, butterflies, and hummingbirds visit them. The fruit is a small, narrow capsule with a leathery wall. It splits open to release many seeds. These seeds are reddish brown, with pits on their surface.

Grow this shrub in sun or partial shade with good drainage. Shelter it from harsh sun in hot sites. It accepts several soil types and a broad pH range. Regular moisture gives better growth, though it withstands some drought. It also tolerates heat and some salt. Sources place it in USDA zones 9–11 and RHS hardiness class H2. Cold can kill the top growth in zones 8–9. Mulched plants may sprout again from the base. In cooler areas, gardeners use it as summer bedding or a houseplant. Borders, ground cover, pots, and hanging baskets suit its compact form.

Care needs are low, and disease is not a usual problem. Indoor plants can attract mealybugs, thrips, and whiteflies. Flea beetles can strip the leaves, while nematodes weaken plants. No edible use or known hazard is recorded by Useful Tropical Plants. This does not establish that eating it is safe. Traditional uses include leaf and flower preparations for coughs and fevers. People also use these parts as an insecticide.