False Heather (Cuphea hyssopifolia)

Elfin Herb, False Heather, Hawaiian Heather, Mexican Heather

Cuphea hyssopifolia, commonly known as Mexican heather or False Heather, is a low-growing evergreen shrub that produces delicate, tubular flowers in shades of pink, purple, and white. The plant is native to Mexico and Central America, but is widely grown as a garden plant in many parts of the world due to its attractive appearance and adaptability to different soil types and growing conditions.

I. Appearance and Characteristics 

Cuphea hyssopifolia, the false heather, Mexican heather, Hawaiian heather or elfin herb, is a small evergreen shrub native to Mexico, Guatemala, and Honduras.

Small, trumpet-shaped flowers bloom with six spreading petals, usually lavender, and green calyx tubes from summer to frost on a multi-stem plant reaching up to 2 feet tall and 4 feet wide when mature. Leaves are lance-shaped, glossy, and green, measuring about a quarter of an inch long. The fruit is a capsule that contains small globose seeds.

The Latin specific epithet hyssopifolia (which also occurs in several other plant names, including that of Bassia hyssopifolia) means “hyssop-leafed”, referring to the fine, narrow leaves of that plant.

It is present in hot, semi-warm and temperate climates between 500 and 2240 meters above sea level. An ornamental plant grown in orchards and gardens, it grows on the banks of streams, associated with disturbed vegetation of tropical deciduous and sub-deciduous forests, as well as mountain mesophilic forest.

The species is naturalized in Hawaii, and regarded as a serious weed there.

In cultivation, the species adapts to a range of soils in a sunny or partially shaded situation with good drainage. It can be cultivated outdoors in USDA hardiness zones 8B-11, but does not tolerate freezing temperatures. In colder regions it may be cultivated as an annual. Plants may be propagated by cuttings, layering or division. They seed freely, and new seedlings that appear are easily transplanted.

This plant has gained the Royal Horticultural Society’s Award of Garden Merit (confirmed 2020).

II. How to Grow and Care

Plant Mexican Heather only after the soil has warmed. Use as a container plant, a border plant, along walkways, or in small spaces. This small shrub can also hang attractively in a basket. Group it in pots around a patio, a pool or other water feature.

Sunlight

Cuphea hyssopifolia thrives in full sun to partial shade. It requires at least 4-6 hours of direct sunlight each day for optimal growth and flowering.

Place False Heather in a location that receives ample sunlight throughout the day.

Temperature and Humidity

Evergreen in warm climates or indoors, Mexican Heather is hardy in USDA Zones 9b through 11. Growing best in temperatures above 55 degrees Fahrenheit, it tolerates high summer heat and some drought. It will not tolerate frost, but it can survive chilling temperatures as low as 35 degrees. Mexican Heather may survive in Zone 9a if protected from hard freezes. In colder climates, grow this plant as an annual.

Watering

False heather should be watered deeply approximately once a week. The soil should be allowed to partially dry out in between waterings. This species requires more frequent watering in the summer months if it’s planted in a container as opposed to being planted in the ground. The soil should be kept consistently moist.

Soil

Plant Mexican Heather in average, well-drained loam or clay. Slightly acidic soil is best with a low pH between 5.5 and 7. In desert alkaline soils common to the dry heat of Phoenix, the plant may be prone to yellow leaf chlorosis. Amend the soil by mixing in peat moss or using acid forming fertilizers.

Fertilizing

False heather should be fertilized with a slow-release, organic fertilizer. This type of fertilizer can be added once per year in the spring season. If a liquid fertilizer is preferred instead, it can be added during waterings in the spring and summer seasons. Fertilization will promote healthier, fuller growth of this species.

Planting

Planting Mexican heather is uninvolved, although the plant benefits from a little added compost or manure if soil is poor. Allow at least 18 inches (46 cm.) between each plant. This tough, drought tolerant plant loves direct sunlight and thrives in intense heat. Remember that although Mexican heather plants grow in a wide range of soils, good drainage is critical.

Pruning

Cuphea hyssopifolia benefits from regular pruning to maintain a compact and bushy shape. Prune back leggy or overgrown branches to encourage branching and promote a denser growth habit.

Trim False Heather lightly after each flowering period to promote new growth and enhance its appearance.g.

Propagation

Propagation of Cuphea is from seeds, cutting, or division.

To propagate by seed, fill 4″ inch pots with a standard potting mix.

  • Thoroughly moisten the soil and place several seeds on top.
  • Gently apply a thin layer of soil over the seeds.
  • Place the pots in a spot receiving at least eight hours of indirect sunlight each day.
  • After the seedlings appear and are strong enough to remain upright in light wind, transplant them outdoors or to larger containers.

To propagate from cuttings, cut a four to 6″ inch branch.

  • Remove the lower leaves from the cutting and dip the cut end in rooting hormone powder.
  • Place the tip in the soil in a 4″ inch pot.
  • Water once or twice per week until the plant takes root.
  • After the root system is established, transplant it to larger containers or plant outdoors.

Propagating by division requires established Mexican heather plants.

  • Carefully dig the soil around the plant to protect the roots.
  • Gently pull the plant from the ground.
  • Place the plant on its side and use a sharp knife to divide the root ball into three or four pieces.
  • Plant each section in the ground or in suitable containers.

Pests and Diseases

Mexican heather isn’t susceptible to most pests.

The main issue to watch for is an infestation of flea beetles.

Flea beetles leave small holes in the leaves and stems, making the plant less attractive.

The damage may eventually kill the plant.

Spider mites, caterpillars, and nematodes are common pests that also attack the plant.

They are more likely to appear when growing Mexican heather indoors. These pests usually leave a barren of leaves.

If either pest appears, spray the plant with water. If the infestation becomes severe, start applications of Neem oil sprays for plants.

The water should dislodge and drown the critters.

Misting the plant daily reduces the risk of pests in the first place.

Another issue to pay attention to is the spread of the plant.

False Heather self-seeds profusely, potentially making it invasive.

In fact, it’s considered an invasive weed in Hawaii.

Avoid growing the plant in spots where it may spread easily or remove seedlings as they appear.

III. Uses and Benefits

  • Ornamental uses 

Cultivated as a perennial in warmer climates and an annual in colder ones, false heather is a common border, potted, and hanging plant. Its multitude of long-lasting bright flowers and appeal to birds and butterflies make it popular in all types of gardens. False heather can be used to bring a pop of color to an otherwise uninteresting area, such as a patio or deck. Primroses, snapdragons, and angelonias make for lovely companions.

  • Other uses 

It is also a valuable source of nectar for bees, butterflies, and other beneficial insects.

False Heather (Cuphea hyssopifolia) Details

Common name Elfin Herb, False Heather, Hawaiian Heather, Mexican Heather
Botanical name Cuphea hyssopifolia
Plant type Annual
Hardiness zone 9a, 9b, 10a, 10b, 11a, 11b
Growth rate Medium
Height 1 ft. 0 in. - 2 ft. 0 in.
Width 1 ft. 0 in. - 2 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Clay
Flower color Pink
Leaf color Green