Mexican Heather – Cuphea hyssopifolia [KYOO-fee-uh, hiss-sop-ih-FOH-lee-uh] is a small shrub belonging to the Lythraceae family and Cuphea genus.
It’s native to Mexico, Honduras, and Guatemala.
Cuphea hyssopifolia has several common names:
- Mexican heather
- False heather
- Elfin herb
Mexican heather cuphea has been naturalized in Hawaii, where it’s often called Hawaiian heather.
All the cultivars grow outdoors easily in the southern United States but require indoor cultivation in colder regions.
No matter where it grows, it brings a showy bloom of bright purple or lavender flowers during the summer.
- How Big Does Mexican Heather Get?
- Flowering and Fragrance
- Light and Temperature
- How Often Do You Water and Fertilize Mexican Heather Cuphea?
- Soil and Transplanting
Care and Maintenance of Mexican Heather
How Big Does Mexican Heather Get?
- Mexican heather, usually grown as an annual, is a tropical shrub reaching a height of about 1′ to 2′ feet.
- It typically spreads up to 2.5′ feet and features evergreen foliage.
- The plant has many branches and tends to develop a rounded shape.
- The lance-shaped leaves are evergreen, remaining on the shrub year-round.
- The glossy green leaves may reach up to ¾” inch long.
Flowering and Fragrance
The trumpet-shaped Mexican heather purple flowers with six petals and green calyx tubes arrive in the summer.
The purple or lavender petals often attract butterflies and hummingbirds.
You’ll find the trumpet-shaped flowers in the leaf axils along the stems. Mexican heather blooms profusely from summer until the first sign of frost.
Light and Temperature
Grow Mexican heather in sunny locations with warm climates. It can tolerate high summer heat and full sun.
The planting location for outdoor plants should receive several hours of direct sunlight in the afternoon and partial shade for part of the day.
Mexican heather is winter hardy in USDA hardiness zones 9 to 11.
It cannot survive freezing temperatures.
In colder regions, move the plant indoors after the flowers drop. You can apply a thin layer of mulch to keep the weeds in check and minimize moisture evaporation.
Move this evergreen shrub outside after the last threat of frost.
How Often Do You Water and Fertilize Mexican Heather Cuphea?
Maintain a consistent schedule for watering Mexican heather, especially for younger plants.
Water once or twice per week, ensuring the soil remains consistently moist.
Once established, the plant may no longer require frequent watering, and it even becomes tolerant to drought.
Use organic fertilizer to promote fuller, healthy growth in early spring. Another option is to add liquid fertilizer with each watering throughout the spring and summer.
Soil and Transplanting
Mexican heather adapts to a variety of soils, including sandy or loamy soil. But it likes well-drained soil.
Slightly acidic soil with low ph levels between 5.5 and 7 is also the best.
Add a layer of mulch around the base of the plant to increase water retention and prevent the spread of weeds around the root system.
Mulch also protects against colder temperatures in freezing conditions during the winter.
Occasional grooming helps produce denser growth. If the plant appears leggy, trim back the branches by a third of its current height.
You can also prune the Mexican heather plant to maintain its shape and tidy appearance.
Groom the plant in the spring or fall, outside the main growing season, and in the late winter.
Another Cuphea of interest: Cigar Plant (Cuphea ignea)
How To Propagate Mexican Heather Cuphea
Propagation of Cuphea is from seeds, cutting, or division.
To propagate by seed, fill 4″ inch pots with 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.
Mexican Heather Cuphea 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.
Suggested Mexican Heather Uses
Use Cuphea hyssopifolia for ground cover, walkways, borders, beds, or other water features.
Plant Mexican heather along edging paths or grow as a container plant on patios and decks.
They also make attractive hanging baskets or border plants in small spaces or along walkways.
When planted as a small hedge or edging, the Mexican heather helps define pathways and softens the sidewalks and corners of paving.