How to Plant, Grow, and Care for Mexican Heather

Mexican heather is a small evergreen shrub that is native to Mexico. It tolerates high summer heat and prefers full sun. This low-maintenance perennial in warm climates can also be grown as an annual in milder climates. This small shrub makes an excellent border variety and is a fantastic addition to any pollinator garden. It has small white, pink or purple flowers. 

Mexican heather is also known by many other nicknames, such as Hawaiian heather, elfin herb, or false heather. It is most commonly identified by its bright green foliage and lavender flowers. This shrub tends to grow in a rounded shape and makes an excellent ground cover. Its lance-shaped leaves often cause confusion between this false heather and true heather. 

Mexican heather do well in pots and, therefore, also make great container specimens because of their compact size and low growth profile. They will flower year-round in tropical climates, but in areas that receive below-freezing temperatures, they will need to be transplanted in early spring and will have a shorter growing season. They prefer well-drained soil and full sun so find a sunny spot in your garden or on your deck and enjoy this evergreen shrub, its beautiful small flowers, and all of the pollinators that it will bring to your garden. 

Plant Overview

Plant Type Shrub Family Lythraceae Genus Cuphea Species Cuphea hyssopifolia	Native Area Central America Exposure Full sun Height 2′ Watering Requirements Moderate	Pests & Diseases Flea beetles, spider mites, possibly aphids Maintenance Low Soil Type Well-draining, fertile to sandy Hardiness Zone 9-11

What is Mexican Heather?

Mexican heather (Cuphea hyssopifolia) is also referred to as Hawaiian heather, false heather, and elfin herb. It readily self-seeds and will spread when provided with the right conditions. Species in the Cuphea genus are known to attract hummingbirds and butterflies with their nectar-filled flowers. 

Native Area

As its name suggests, Mexican heather originated in Mexico and has a native range that extends into parts of Central and South America, but it has also become naturalized in Hawaii and can even be considered a weed. It is also commonly seen throughout the landscape in southern California.

Characteristics

Mexican heather has bright green leaves and small flowers. Green calyx tubes enclose the flowers until they are ready to bloom. Although they can also come in varieties that produce pink and white flowers, purple flowers are the most common. This shrub grows best in tropical regions and can survive as a perennial in warm climates. In cooler climates, it is recommended to wait until the last threat of frost has passed before transplanting out this tender summer shrub. 

Cuphea hyssopifolia is mainly added to a landscape for ornamental purposes. However, the cuphea genus is being studied for its ability to improve the soil for specific crops via crop rotation practices. Planting cuphea before planting wheat or corn has been shown to increase yields. In the garden, it is easy to grow in containers, has few serious pests, is relatively low maintenance, and will thrive when it is well watered and placed in an area that receives direct sunlight.

Planting

Choose a well-draining soil and a location that receives full sun for growing Mexican heather. Dig a hole slightly larger than the root ball and place it inside. Backfill with soil, gently pressing down to remove air pockets. Water thoroughly after planting and apply a layer of mulch to retain moisture.

How to Grow

As mentioned above, Mexican heather care is relatively easy. It’s happy to absorb as many hours of direct sunlight as possible as long as it remains in well-watered, well-drained soil. Grow Mexican heather if you’d like to add these lavender flowers to your growing season. 

Light

Since Mexican heather is native to Mexico and South America, it tolerates high summer heat and needs six to eight hours of direct sunlight per day. It has been known to be hardy enough to tolerate partial shade, although it may not bloom as intensely. Conversely, an area with too much direct sunlight may result in the foliage not reaching its full potentially bright green color.

Water

Once Mexican heather begins to bloom, it’s important to water regularly, at least weekly, if not twice a week, during periods of drought. It’s best practice to water in the morning so that the water has a chance to soak into the ground before evaporating during the heat of the day.

As with most species, avoiding wetting the foliage is a good idea to avoid the risk of disease and other foliar problems. For this reason, and because it can grow low to the ground, it’s easiest to water with drip irrigation systems. This will ensure they receive a deep soak while avoiding the abovementioned issues. Since Mexican heather can bloom year-round, it also requires year-round watering, though watering can be cut back during cooler periods. 

Soil

Mexican heather can thrive in a variety of well-draining soils (loam, clay, sandy). In its natural habitat, it generally grows in sandy, slightly acidic soil. Providing it with good drainage is probably the most important part of maintaining its overall health. Surrounding the base with a thin layer of mulch will help the soil retain moisture and decrease the need to water as frequently. 

Temperature

It does best in tropical climates that average 75-85°F (24-29°C). For this reason, grow Mexican heather in USDA hardiness zones 9-11. It is extremely sensitive to frost and will not survive a light freeze (when temperatures reach 32°F or 0°C). It can survive extreme heat and even if parts die back, it will return yearly in tropical regions. 

Fertilizing

Mexican heather care is low maintenance. Fertilizing is not necessary unless a poor soil condition exists. In that case, a granular slow-release fertilizer at the beginning of the season will suffice. Adding a thin layer of organic matter around the base each year will help retain soil quality.

Maintenance

Mexican heather are a very low-maintenance shrub when it comes to pruning. This small shrub doesn’t require any pruning at all, however, if it begins to look overgrown or if you would like to give it a more rounded shape, then it can be lightly pruned in the early spring. The tips of branches can also be pruned back in early spring or late winter to encourage bushier growth. 

Propagation

Mexican heather is known to self-seed readily, and for this reason, it can spread uncontrollably if left unchecked. It can also be propagated by taking cuttings. Snip a healthy branch and place it directly into a pot of soil or glass of water until roots develop, then set it in its new location.

However, the easiest way to propagate is to dig up the entire shrub, including the root ball, and cut it in half vertically. Then, the two halves can be replanted. 

Common Problems

As mentioned above, providing this shrub with good drainage, full sun, and fertile soil will result in healthy species. There are,  however, some issues that can crop up. 

Growing Problems

As mentioned above, Mexican heather care is very low maintenance. However, root rot can become an issue when it is located in an area with poor drainage. Overwatering can contribute to this issue as well. The bright green leaves are an indicator of overall health. If they begin to turn yellow, this may be a sign it is being overwatered. When growing in containers, be sure that there are drainage holes in the bottom to help avoid this issue as well. 

This false heather is not frost-hardy at all. Once the temperature reaches 32°F (0°C), it will suffer frost damage, and once the soil freezes, it will die completely. If it’s being grown in any USDA hardiness zones that receive freezing temperatures, it’s recommended to only set it out in the spring after the last threat of frost. If a late spring frost should arrive after it has been planted, provide it with a cover or bring it indoors.

Pests

The most common pest issues are spider mites, flea beetles, and other small soft-bodied insects that feast on foliage, like aphids. Spider mites are most likely to appear that are grown indoors since they’ve been removed from an environment where their natural predators would keep them in check. Neem oil will kill them, and their eggs, on contact. Insecticidal soap can also be used. Spray once a day every few days until they have all been killed. Flea beetles and aphids are more of a nuisance than a real threat to this plant. Spraying them off with water will get rid of these pests. 

Frequently Asked Questions