Earth Stars - Cryptanthus

Cryptanthus bivittatus - Copyright: Nuno & Green

Contents

1. Top Tips
2. Location, Water, Humidity & Fertilisation
3. Common Issues
4. Origins, Temperature, Propagation, Repotting & Toxicity.

Need the answer to a specific plant query? Book a 1-to-1 video call with THE HOUSEPLANT DOCTOR™, the website's friendly author, to overcome and address your niggling problem! Available on iMessage, WhatsApp, Facebook Messenger & more.

Top Tips & Info

• Care Difficulty - Very Easy
• No direct sunlight; a bright, indirect setting is more than enough to occupy a Cryptanthus as exposure to the intense rays will burn its foliage.
• Keep the soil evenly moist, allowing the top third to dry out in between waters. Keep those situated in darker environments on the drier side to life due to the small risk of 'heart rot' when excess moisture sits within the plant's body.
• Fertilise using a 'Houseplant' labelled feed every four waters in the spring and summer, reducing this to every six in the colder months.
• Repot every two years using a 'Houseplant' potting mix; this is the perfect time for propagation and a quick check on the root/soil health.

Location & Light - 🔸🔸

During the spring and summer, be sure to provide a brightly lit spot away from any direct light. Excessive exposure during this time will negatively affect the plant in the likes of sun-scorch and dehydration. Once the autumn kicks in, be sure to include an hour or two of direct light per day to get it through the dormancy period, lasting until the following spring.

Water - 🔸🔸

Allow the top third of the soil to dry out between waters, reducing this further in the autumn and winter. Under-watering symptoms include pale leaves, brown leaf patches, sunken foliage and crisping flowers; these issues are typically caused by intense sun or heat, being potbound, or pure forgetfulness. Over-watering symptoms include a rotten stem with yellowing leaves, flower collapse and 'pup' death. Possible reasons for the decline are too little light or heat, excess moisture within its foliage and a lack of drainage.

Humidity - 🔸🔸

Although Cryptanthus will accept average room humidity, introduce a pebble tray to provide a moist and stable environment for your plant. If the surrounding saturation is too low or the heat too high, its leaf-tips may start to brown over and curl, especially in direct sunlight. Hose the foliage down from time to time to hydrate the leaves and keep the dust levels down. 

Those situated in a terrarium won't require misting or use of a pebble tray due to the proximity of other plants and higher levels of transpiration.

Fertilisation - 🔸

Fertilise every four waters during the growing period before reducing this to every six in the autumn & winter. Although an 'All-Purpose' fertiliser will still do the job, we'd recommend using a specific 'Houseplant' labelled fertiliser as it'll support the vital thirteen nutrients that this species will need to grow.

Common Issues with Cryptanthus

Yellowing older leaves (closest to soil) and crown rot are a clear sign of over-watering, usually caused by too little light. Although Cryptanthus can do well in darker locations, the frequency of irrigations must be reduced to counteract the chance of root rot. People don't realise that a plant's root system needs access to oxygen too; when soil is watered, the air will travel upwards and out of the potting mix. A lack of accessible oxygen for the roots will cause them to subsequently breakdown over the oncoming days. Click on this link to learn more about root rot and how to address it.

Curled leaves and brown leaf-edges are the result of too little water and over-exposure to the sun. Cryptanthus are best located in bright, indirect settings, and those that haven't acclimatised to the harsh rays will show signs of sun-scorch and environmental shock. A splash of winter sunlight is acceptable as long as the soil moisture is regularly observed, with complete avoidance once summer comes along.

Clean the leaves regularly. Although this isn't too much of an issue, a build-up of dust particles can clog up the plant's pores, causing lowered light capturing-efficiency. Rinse the topsides of the leaves down once a month to keep levels down and improve growing conditions.

Mould developing on the soil means two things - too little light and over-watering. Despite the harmlessness, it'll prove unsightly to most gardeners and is therefore removed once known. To remove, replace the top two inches of the soil for a fresh batch of 'Houseplant' compost. Either increase the amount of light received (no direct sunlight for the first few weeks to prevent environmental shock) or decrease the frequency of waters slightly. If the mould is accompanied by yellowing lower leaves, you may also have a case of root rot.

Origins

Cryptanthus is a genus of seventy flowering species, endemic to eastern Brazil. The genus was first described back in 1836 by Christoph F. Otto during a visit to South America. The name originates from the Greek words for 'hidden' and 'flowers', that refers to the compact-nature of its blooms.

The Distribution of Cryptanthus

Temperature 

15° - 30°C   (59° - 86°F)
H1a (Hardiness Zone 13) - Should be grown indoors or under glass all year round. Never allow temperatures to dip below 15℃ or permanent damage may occur in the likes of flower loss, stunted growth and yellowed leaves.

Spread

Smaller species will only achieve 15cm in height and width, whereas their larger counterparts can surpass 50cm. Maturity can be reached within eight years.

Pruning & Maintenance

Remove yellow or dying leaves, and plant debris to encourage better-growing conditions. While pruning, always use clean utensils or shears to reduce the chance of bacterial and fungal diseases. Never cut through yellowed tissue as this may cause further damage in the likes of diseases or bacterial infections. Remember to make clean incisions as too-damaged wounds may shock the plant, causing weakened growth and a decline in health.

Propagation

Via Seed or 'Pup' Propagation.

Basal Offset Division (Easy) - Your plant will produce several basal offsets that can be separated once they have a sufficient root system and surpass the mother plant's height by half. If possible, water the soil 24hrs before the main event to reduce the risk of transplant shock, when its dry root systems are over-touched. Take the plant out of its pot and place your fingers close to the nodal junction - compost may have to be removed for better access. Push the chosen offset downwards until you hear a snap. Separate the foliage and its root system away from the mother plant, mentally noting the high risk of damage. Transplant in the appropriate sized pot with a fresh batch of 'Houseplant' labelled compost. Maintain evenly moist soil and situate it in a bright, indirect location away from any direct sunlight. After four weeks, treat it like a healthy specimen, following the care tips above!

Flowers

The individual specimen will only flower once, with pups forming at the plant's base that'll eventually bloom themselves. The spring inflorescence will remain within the foliage-line, proving rather uninspiring in the meantime. The bract's colours include red, yellow, green, brown, purple or pink that are arranged in a coned-shape. This genus is predominantly grown for its striking foliage and easy-care nature.

Repotting

Repot every two years in the spring, using a 'Houseplant' labelled potting mix and the next sized pot with adequate drainage. Hydrate the plant 24hrs before tinkering with the roots to prevent the risk of transplant shock. For those that are situated in a darker location, add a thin layer of small grit in the pot's base to improve drainage and downplay over-watering. Click here for a detailed step-by-step guide on transplantation, or via this link to learn about repotting with root rot.

Book a 1-to-1 video call with THE HOUSEPLANT DOCTOR™ if you'd like a personal guide to repotting your houseplant. This will include recommending the right branded-compost and pot size, followed by a live video call whilst you transplant the specimen for step-by-step guidance and answer any further questions!

Pests & Diseases

Keep an eye out for mealybugs, spider mites, scale, thrips & root mealybugs that'll locate themselves in the cubbyholes and undersides of the leaves, with the exception of the latter in soil. Common diseases associated with Cryptanthus are root rot, leaf-spot disease, botrytis, rust, powdery mildew & southern blight - click here to learn more about these issues.

Toxicity

This plant is slightly poisonous. If parts of the plants are eaten, vomiting, nausea and a loss of appetite could occur. Consumption of large quantities must be dealt with quickly; acquire medical assistance for further information. Although the leaves may look delicate from online pictures, its foliage and flowers can be very sharp, acting like small Swiss-army knives when touched. 

Retail Locations

Online Stores.

Book a 1-to-1 Call with THE HOUSEPLANT DOCTOR™

If you need further advice with your houseplants, book an advice call with ukhouseplants' friendly and expert writer today! This can be done via a video or audio call on most apps, including Facebook, FaceTime & Skype. A ten-minute call costs £5.99 (US$7),  or £15.99 for thirty minutes. You can ask multiple questions, including queries on plants, pests, terrariums, repotting advice and anything in between. Please consider supporting this service to keep ukhouseplants thriving!