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. If you live in the right zone, plant bromeliads outdoors in spring or summer. 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. 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 the best place to plant or place bromeliads within this genus will generally be in some sort of spot with 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
Avoid regular potting soil for terrestrially-grown bromeliads. 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. If the plant is watered excessively at low temperatures, rot may occur. The mother plant can also be watered by keeping fresh water in its cup (the middle of the plant towards the bottom, and is also called a tank). The standing water, however, can attract pests. To avoid this, replace the water in the cup weekly and gently remove any dust, debris, and dead insects from the cup with a moist paper towel.
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 regular 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.
Types of Cryptanthus
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 the rainbow star, is bright and colorful. When you are choosing a plant, note that the botanical names of bromeliad species often offer clues as to the appearance of a type of Cryptanthus. Terms commonly found include:
Bivittatus: having two stripesCoriaceous: feather-likeLacerdae: tatteredLatifolius: wide leavedMarginatus: having marginsZonatus: having zones or bandsSurantiacus: orangeCarnosus: pink (meat-colored)Fuscus: dark, duskyViridis: greenAcaulis: stemlessBromelioides: like a bromeliaScaposus: having a scapeSinuosus: sinuous or winding
Potting and Repotting Cryptanthus Bromeliads
Bromeliads prefer somewhat acidic soil, such as that provided in any peat-based commercial potting soil (avoid regular soil without peat). Plant them in a terracotta pot with good drainage, large enough for the offsets that will appear around the mother plant after it blooms. Terracotta works best because the porous material can offer the plant a bit of oxygen to the roots to avoid rotting. 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
Repotting the plant’s pups is the only means of propagating this plant. 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.
Common Pests and Plant Diseases
Like many houseplants, bromeliads can be subject to whiteflies, mealybugs, and spider mites, which are all best treated with organic horticultural oil. Bromeliads are not affected by many diseases. The most common diseases, however, are the fungus causing crown and root rot, leaf spot, and rust disease (affecting the bottom and top sides of leaves).
Common Problems With Bromeliads
Bromeliads are stunning when they are healthy, but a few problems can affect them whether they live indoors or outdoors. Inspect your bromeliad every so often to see if the following problems are occurring:
Dull Color
If your bromeliad doesn’t have brilliant color, it is not getting enough light.
Turning Brown
There are several reasons why a bromeliad’s leaves turn brown. It could be the mother plant has run its course and is dying. If the pups around the mother plant look good, then that is likely the case. Other causes of browning include:
A browning plant may mean the air is too dry.Brown, mushy leaves may mean the medium is too wet.Brown, limp leaves may also be a sign of leaf spot.
Dying Flower
A spent bloom is normal and it means the mother plant’s life cycle is coming to its end. You can remove the flower with a sharp, sterile cutting tool and toss it in the garbage. Now, the plant will have more energy to produce pups.
Papery Leaves
Hot, dry conditions can cause the leaves to twist and become papery.
Drooping Plant
The plant will droop and fade if it doesn’t get enough light. Wilting leaves may also be a sign of root rot.
Unpleasant Odor
If your plant smells bad, it may have a case of crown rot. The unpleasant odor will be coming from the plant’s cup. Inspect the cup because the crown of the cup may look soggy or brownish. It may be too late to save the plant, but see if there are salvageable pups to propagate.
