How to Grow Cryptanthus Bromeliads (Earth Stars) Indoors

cryptanthus varieties

The Spruce / Kara Riley 

Cryptanthus bromeliads, more commonly known as earth stars due to rosette-shaped arrangement of the leaves and their low growth habit, are beautiful and incredibly varied plants native to Brazil. There are over 1,200 types of bromeliads within the Cryptanthus genus, with a great variety of foliage. Their colors range from dark green to bright pink to red, and they can be banded, spotted, solid, or virtually any other pattern.

Like most bromeliads, Cryptanthus species are mostly grown for their interesting leaves, but they also produce small but beautiful white or pink blooms. The plants bloom only once, however, before the plant produces offsets (pups) and then dies. The life cyle of these plants is about three years from pup to flowering plant.

closeup of cryptanthus varieties
The Spruce / Kara Riley
 Botanical Name Cryptanthus spp.
 Common Name Cryptanthus bromeliad, cryptanthus, earth star
 Plant Type Terrestrial bromeliad
 Mature Size 3 inches to 3 feet (varies by species)
 Sun Exposure Bright indirect light; resents direct sunlight
 Soil Type Bromeliad potting mix
 Soil pH 4.0–6.0 (acidic)
Bloom Time Blooms once only 
 Flower Color White (but generally grown for foliage)
 Hardiness Zones 10–11 (USDA)
 Native Area Brazil

Cryptanthus Bromeliad Care

Different species within the Cryptanthus genus require different care, and it best to look into what your specific bromeliad requires. But each Cryptanthus bromeliad shares a few basic rules for care: They all thrive in humid environments, in temperate areas around room temperature, and grow best with fertilization. Keep these rules in mind, find out what specific care your plant requires, and you’ll be growing beautiful bromeliads in no time. 

Unlike many bromeliads, Cryptanthus plants are generally terrestrial only, which means that they naturally grow in a soil medium rather than being "air plants" that can be mounted to a piece of bark or another object.

Though the plant blooms only once in its lifetime, its propensity to produce offsets means it is possible to keep flowers blooming year-round. Despite the reputation of bromeliads for being difficult to grow, Cryptanthus plants are a very feasible option for any gardener who wishes to enjoy their lovely and diverse foliage. Cryptanthus bromeliads bloom only once before dying, but the offset "pups" can be repotted to create an ongoing supply of plants.

Light

Different Cryptanthus varieties need different levels of light, but most plants within this genus will generally thrive in some sort of indirect sunlight or light shade—remember, they naturally grow under the cover of trees in rainforests. Direct sunlight could potentially bleach the bromeliad’s foliage, or make it appear leathery.

Soil

Commercial potting soil based on peat moss works well for Cryptanthus bromeliads, as it has the necessary acidity. There are also potting mixes designed expressly for bromeliads. Some gardeners grow these plants in a mixture of sand and soil mix, as well—but no matter what the soil, they must be kept damp and the soil must retain water fairly well for best results.

Water

Cryptanthus thrive in tropical conditions, and you should make efforts to keep them moist. Make sure, however, not to rest them in standing water. A moderately damp environment is moisture enough for these plants. But bromeliads are surprisingly tolerant of short periods of drought.

Temperature and Humidity

Cryptanthus makes an ideal houseplant: Keeping them around 60 to 85 degrees Fahrenheit will allow these bromeliads to thrive. Cryptanthus plants are fairly forgiving of swings in temperature. Though temperate conditions are best, many varieties can even survive a winter outside as long as they are not kept below freezing for too long.

As tropical jungle plants, Cryptanthus prefers relatively humid conditions, which you can create by using a room humidifier or misting the plant frequently.

Fertilizer

These bromeliads require regulary fertilization for maximum growth and will thrive on any balanced fertilizer: 10-10-10, 14-14-14, etc. But remember to dilute the fertilizer to a 1/4 to 1/2 strength, otherwise, you risk damaging the plant. Feed them every three weeks.

Cryptanthus Varieties

Cryptanthus is a large genus containing an incredibly wide range of plants; almost any gardener can find a bromeliad that suits their needs. For instance, the 'Black Mystic' bromeliad is known for its dark, intriguing foliage, while the Cryptanthus 'Osiris', also known as rainbow star, is bright and colorful.

The botanical names of bromeliad species often offer a clue as to the appearance. Terms commonly found include:

  • Bivittatus = having two stripes
  • Coriaceous = feather-like
  • Lacerdae  = tattered
  • Latifolius = wide leaved
  • Marginatus = having margins
  • Zonatus = having zones or bands
  • Surantiacus = orange
  • Carnosus = pink (meat-colored)
  • Fuscus = dark, dusky
  • Viridis =green
  • Acaulis = stemless
  • Bromelioides = like a bromelia
  • Scaposus = having a scape
  • Sinuosus = sinuous or winding

Potting and Repotting Cryptanthus Bromeliads

Bromeliads prefer somewhat acidic soil, such as that provided any peat-based commercial potting soil. Plant them in a pot with good drainage, large enough for the offsets that will appear around the mother plant after it blooms.

There is no reason to repot a bromeliad, as it will die after blooming. The original pot can be used to grow one of the offshoot pups after the mother plant is removed.

Propagating Cryptanthus Bromeliads

After the mother plant blooms and sends out offshoot pups, wait for the pups to develop small root systems of their own. Then sever the pups carefully and repot them individually, making sure they have begun to form their own central cup; this shows they are ready to grow independently. Their root systems will grow approximately as wide as the foliage, so make sure the pot is large enough. Take note, as well, to keep the pups moist in their infancy.

There is no other common means of propagating these plants.

Common Pests/ Diseases

Like many houseplants, bromeliads can be subject to whitefly, mealybugs, and spider miters, best treated with organic horticultural oil.

If the plant is watered excessively at low temperatures, rot may occur. Hot, dry conditions can cause the leaves to twist and become papery, and the plant will droop and fade if it doesn't get enough light.

varieties of cryptanthus
The Spruce / Kara Riley