Croton petra [KROH-tun, pet-RAH] are broadleaved evergreen plants belonging to the family Euphorbiaceae.
Croton petra is just one of several different available croton varieties of the attractive and interesting croton plant.
You may also hear these types of plants referred to as Joseph’s Coat because of their vibrant color leaves.
These seasonal bloomers are perennials, but they are most often used as annual plants outside of their native tropical settings.
Crotons hail from Malaysia, Sri Lanka, southern India, and Asia.
They may also be found growing wild in northern Australia and the Pacific islands.
We’ve written on the plant care of some of these other popular varieties:
Croton Petra Care
Size & Growth
In nature, these woody-based perennials may grow to be 6’ feet tall, but when kept as a houseplant, they are unlikely to grow taller than 4’ feet.
It has lance-shaped or oval leaf shapes and may grow to be 18” inches long.
The colorful leaves are smooth-edged, leathery and glossy, available in a wide range of color combinations including:
Colors appear in many different and interesting combinations and patterns.
Flowering & Fragrance
The plants’ blossoms are small and insignificant.
They may appear during the growing season, trim them back to enhance the appearance of the plant.
Light & Temperature
Joseph’s Coat likes indirect bright light.
It’s important to hit a happy medium with these plants because they need a great deal of light to maximize leaf color, yet they must be protected from direct high light because in nature they are forest understory plants.
Harsh, full sun will scorch the leaves.
Croton petra should have between four and six hours of bright, indirect sunlight daily.
Plants not receiving enough sunlight will become stretched and lanky, and the leaves will not develop bright, attractive colors.
Excessive amounts of shade will cause plain green leaves.
Plants kept in excessively shady areas may also lose their lower leaves.
Croton plants are winter hardy in USDA hardiness zones 11-12.
In these areas, they may be planted outdoors in direct light year-round.
In other hardiness zones, they must be kept as house plants or as container plants moved indoors and out, weather permitting.
Joseph’s Coat plants do best at consistent temperatures ranging between 60° – 70° degrees Fahrenheit (16° C – 21° C).
They can tolerate temperatures up to 85° degrees Fahrenheit (29° C).
If you live in a cooler area, be sure to bring your plant in for the winter when the nighttime temperatures drop to 50° degrees Fahrenheit (10° C).
As an indoor plant, keep your plant away from both cold and hot drafts.
Don’t place houseplants to close to a windowpane in the wintertime as it may get a chill.
Watering & Feeding
As tropical plants, Croton houseplants like high humidity.
Low humidity inside the house makes crotons particularly susceptible to spider mites.
Daily misting is a good idea, and you may wish to keep your potted plant on a tray of wet pebbles to increase the ambient humidity.
As with most plants, it’s best to water thoroughly and occasionally rather than slightly and frequently.
Regular watering is essential, but excessive watering will cause root rot.
They are not as thirsty as other indoor plants but will drop leaves if kept too dry.
Keep the soil slightly moist at all times but never soggy.
Check the soil regularly.
When the top inch becomes dry, water the plant completely until the water runs through the drainage holes.
Refrain from watering again until you find the top inch of soil is once again dry.
It is especially important to be attentive to watering during the growing season (spring through autumn).
Although the plant does not go dormant in winter, you should cut back somewhat on watering to allow it a period of rest.
In the autumn and the winter months, you should only water when the top 2” – 3” inches of soil are dry.
Joseph’s Coat are not heavy feeders.
Use a general houseplant fertilizer, preferably slow-release, seasonally throughout the growing season.
Do not fertilize at all during the late autumn or throughout the winter.
Early in the spring, provide a feeding then do so once again in early summer and again in late summer.
Soil & Transplanting
Soil should be well draining with some loam mixed in for water retention.
Indoors, any good quality potting soil mix will do well.
Add a layer of pebbles or Styrofoam peanuts in the bottom of the pot for good drainage.
Outdoors be sure to choose a location providing good drainage.
Soil should be humus-rich.
Avoid transplanting unnecessarily as these plants are very sensitive to disruption and go into shock easily.
Grooming & Maintenance
Croton require little grooming and maintenance.
You may wish to prune occasionally to control size and shape.
Be sure to use a very sharp set of pruning shears or scissors, and keep them very clean.
If leaves are damaged, just cut off the damaged part; however, your plant will retain a better overall appearance if you cut the leaf back at the base of the stem.
How To Propagate Croton Plants
New croton may be propagated from a leaf or stem cuttings.
Choose a cutting with new growth on it.
Use of rooting hormone will help you grow croton quicker.
Root cuttings in new pots of slightly moist soil kept in a warm location with bright, indirect sunlight.
Croton Pests Or Disease Problems
Like all of its cousins, petra croton is subject to shock.
Your plant may lose leaves in transit from the nursery to the seller (garden center) and again after you buy it and bring it home.
Don’t be too alarmed; this means your plant is going through an adjustment (acclimation) period.
Take care to choose the right setting for it initially and don’t move it around a lot once you get it home.
Provide consistent temperature, light, and water, and your plant will soon recover.
Improper watering can cause many problems for Crotons.
Leaves may wilt if the plant is overwatered, so resist your instinct to give your plant more water if you see wilted leaves.
Instead, inspect the soil. If you find it to be wet, move your plant to improve air circulation by adding an indirect breeze from a small fan set on low and turned away from the plant.
This will help excessive water in the soil to evaporate.
Remember overwatering will also cause root rot.
Croton leaves may also turn brown and become crispy.
This is due to low humidity and too little water.
A lack of humidity may also cause leaf spot disease.
Crotons may be subject to leaf spot disease.
If you see your plants’ leaves are marred by brown spots with yellow edges, this may be an indication too much salt has built up in the soil.
Flush the soil thoroughly with water (rainwater is best) to remove salt buildup.
Repotting may require fresh soil.
If you have over watered, plants may develop symptoms of fungal or bacterial infection.
To treat this, prune away infected leaves and take great care when watering not to allow any water to come in contact with the foliage.
Be sure to increase air circulation around your plants.
Excessive watering and lack of good air circulation may also cause your plants to become susceptible to attacks by:
Is Croton Petra Toxic Or Poisonous?
Codiaeum variegatum ‘Petra’ is somewhat toxic to people and pets.
Keep the plants out of reach of children and animals because ingestion may cause gastric distress, diarrhea, vomiting, and a burning sensation in the mouth.
When you prune your plant, be sure to wear gloves and wash up afterward as the sap may be irritating to your skin.
Is Croton Invasive?
While Croton may naturalize in USDA hardiness zones 11-12, it is not considered invasive in these areas.
Suggested Uses For Petra Crotons
In USDA hardiness zones 11 and 12, these plants can do well as understory plants under trees providing partial shade.
Croton of all sorts are an excellent choice as an indoor plant as long as 4-6 hours daily of bright, indirect natural or artificial light is available.
Do not plant Joseph’s Coat in areas having a lot of salt in the air or soil, as they are saline intolerant.
Remember they are forest under story plants, so they are not a good addition to a seaside garden.