Looking at Plants

Codiaeum variegatum ‘Congo’

COMMON NAMES

Congo Croton

Codiaeum (co-dye-EE-um) – Greek for head, referring to the use of croton leaves for wreathes

variegatum (vare-ee-a-GAY-tum) – variegated, referring to the mottled leaves

‘Congo’ – cultivar name

GROUP 

Dicot

FAMILY 

Euphorbiaceae

ORIGIN

Species – southeast Asia, Indonesia, and nearby islands

DESCRIPTION

Congo Croton is an evergreen shrub that is dense and compact when young. It can become more rounded and leggy when larger. With a slow growth rate, this cultivar averages 5 to 6 feet high and 3 to 4 feet wide.

The highly variable leaf colors are the strong point of the croton. This cultivar shows red, orange, yellow, burgundy, and green. The veins are often prominent in reds, oranges, or yellows. Leaves are alternate to spiral in arrangement, large, and elliptical to oval in shape. As with many plants in the Euphorbia family, crotons have a very milky sap.

Flowers are inconspicuous, small, yellow to white in color, and star-shaped. They are borne on racemes from the axils. Summer is the usual bloom time.

Fruit of the croton are brown, round capsules.

HARDINESS

Hardy in USDA Zones 9b to 11, the many cultivars of croton are somewhat variable in cold tolerance. The cold tolerance of ‘Congo’ is not yet documented. A lot depends on the age of the plant and its microenvironment. As a tropical plant, crotons have very good heat tolerance.

LIGHT

In general, crotons will grow in sun or shade. Brighter colors tend to come with more light and slightly cooler temperatures; colors tend to wash out and fade in full sun with hot temperatures. Brighter light also brings smaller leaves with shade bringing larger leaves.

SALT

Slight to Moderate Salt Spray Tolerance – it will tolerate some spray, but it is best to have more protection such as a fence or building as an additional barrier behind the first row of plantings or the first dunes.

SOIL

It prefers a rich, moist soil in the pH range of 6.0 to 6.5, but it will grow on a wide variety of other well-drained soils.

WATERING

Once established, crotons have fair drought tolerance, but they will be much healthier with irrigation in dry spells. Plants grown in shade tend to need less water.

PROPAGATION

Softwood tip cuttings approximately 3 to 6 inches long with 3 to 5 leaves work well. The ideal propagation temperature is 70 to 78 degrees F. The average rooting time under mist and with a rooting hormone is 1 to 2 months. Air layering is alternate method of propagation.

PRUNING

Most crotons can get leggy if not pruned to encourage branching. Pruning should be done selectively by hand. Power shearing does not work well with the form and size of the leaves.

FERTILIZING

It has no special fertilizer needs. Unless a soil test suggests otherwise, a slow-release balanced analysis fertilizer applied per the product label will work. If your soil is fairly high in phosphorus, then a 3-1-2 ratio analysis will work also.

PESTS

Darkwinged Fungus Gnats - University of Florida

Whiteflies - University of California

Citrus Mealybug - University of Florida

Croton Scale - University of Florida

Pink Hibiscus Mealybug - University of Florida

Saddleback Caterpillar - University of Florida

False Spider Mite - University of Florida

Cuban Laurel Thrips - University of Florida

Greenhouse Thrips - University of Florida

DISEASES

Crown Gall - Missouri Botanical Gardens

Xanthomonas Leaf Spot - University of Illinois

Anthracnose - University of California

Botrytis Blight - Missouri Botanical Gardens

Fusarium Wilt and Rot - Missouri Botanical Gardens

Phytophthora Root Rot - North Carolina State University

Pythium Root Rot - Purdue University

DEER

Resistant

There are very few totally “deer-proof” plants. There are also, relatively speaking, few plants that are considered a preferred food supply of deer. Most plants fall in the big gap between. One of the biggest variables is the available preferred food supply in a given area. If their preferred food is scarce, they will munch on most anything.

OTHER

Croton leaves also work well in floral arrangements. Just be a little careful of sap from fresh cut material.

USES

Color accent, foundation plant, specimen plant, containers, tropical effect, mass plantings, borders, hedge

TOXICITY

California Poison Control gives Codiaeum spp. a listing of:

1 - Dermal Skin - contact with these plants can cause symptoms ranging from redness, itching, and rash to painful blisters like skin burns.

North Carolina State University lists as:

Poison Part:All parts

Poison Delivery Mode:Ingestion, dermatitis from milky sap

Symptoms:Allergic dermatitis with skin rash developing after repeated contact. Nausea, vomiting, diarrhea when ingested

Toxic Principle:Diterpene esters

Severity:TOXIC ONLY IF LARGE QUANTITIES EATEN. SKIN IRRITATION MINOR OR LASTING ONLY FOR A FEW MINUTES.

University of California lists as:

Minor Toxicity: Ingestion of these plants may cause minor illnesses such as vomiting or diarrhea. If ingested, call the Poison Control Center or your doctor.

Dermatitis: The juice, sap, or thorns of these plants may cause a skin rash or irritation. Wash the affected area of skin with soap and water as soon as possible after contact. The rashes may be very serious and painful. Call the Poison Control Center or your doctor if symptoms appear following contact with the plants.