How to Grow and Care for Croton Plants

Croton is a tropical plant with colorful variegated foliage and nearly limitless leaf forms with hundreds of croton plant varieties. Croton plants grow best outdoors in warm, humid climates with full to dappled light in soil on the acidic side and with temperatures above 60 degrees Fahrenheit. Outdoor croton plants can reach around 8 feet tall but houseplants are much smaller. However, be careful about where you plant as crotons are toxic to humans and animals. 

Croton Plant Care

There are a few important tips to keep in mind when caring for croton plants.

• Provide steady warmth for croton plants indoors or outdoors.
• Give croton plants plenty of sun to maintain their vibrant leaf colors.
• Keep humidity between 40 to 80 percent.
• Protect croton houseplants from drafts around windows and doors, as well as air-conditioning vents.

Light

Croton plants need a fair amount of sun. Bright, indirect light is best. Some croton plant varieties don't tolerate unfiltered, direct sun as well as others, but they will thrive in dappled sunlight. If the plant is getting insufficient sun, the leaves will turn all green.

Water

Keep croton plants evenly moist in the summer. Crotons need about 1 inch of water per week. Reduce watering in the winter to biweekly. Watch the plant for signs that it needs more water, such as wilting young foliage. Increase watering if the wilting noticeably happens during hot weather, but check the top couple of inches of soil with a finger for moisture before you increase water. If it's still moist, hold off on watering. Mist frequently during the growth period.

Soil

A well-drained, moist soil that has been enriched with compost is ideal for a croton. This plant prefers humus-rich, acidic soil.

Temperature and Humidity

For croton plants indoors, keep the room above 60 degrees Fahrenheit, and do not expose the plant to cold drafts. Lack of humidity and bright light can affect leaf color. Keep the humidity level at 40 to 80 percent. If the humidity isn't high enough, the plant might drop some of its leaves. If you have trouble maintaining the moisture in your home at this level, run a humidifier in the room, place a small plant humidifier nearby, or set a pebble tray beneath the plant.

Fertilizer

Apply slow-release pellets three times per growing season: early spring, midsummer, and early fall. Or you can use a liquid fertilizer every other month during the growing season from early March to the end of September. Because fertilizers vary widely by type, read the package instructions for feeding quantity. In most cases, if you intend to feed on a regular schedule, you can reduce the package-suggested amount by half strength. Then, observe the plant's growth rate over the next month; you can adjust and add or reduce fertilizer depending on how vigorously you want your plants to grow. Stop giving fertilizer during the winter months.

Because this plant prefers slightly acidic soil, use acidifying fertilizers that contain ammonium nitrate, ammonium sulfate, or sulfur-coated urea. Your best target NPK ratios are 3-1-2 and 8-2-10 (nitrogen-phosphorus-potassium).

Types of Croton Plants

There are hundreds of croton plant varieties, with names like 'Dreadlocks', 'Ann Rutherford', 'Mona Lisa', and 'Irene Kingsley.' For a plant with such incredible diversity, it's impressive that there is only one species (Codiaeum variegatum). Each plant is unique due to this plant's genetic instability and variability; enthusiastic collectors highly prize unusual varieties. Crotons are often classified by leaf type: curling, twisted, oak leaf, narrow, broad, and oval. A few notable varieties include:

• Codiaeum variegatum var. pictum: Large, brightly colored leaves of orange, red, bronze, green, purple, and yellow; grows 3 to 6 feet tall as a houseplant
• Codiaeum variegatum 'Gold Star': Narrow, linear leaves of green with bright yellow spotting; has a tree-like habit and grows to only about 20 inches in height
• Codiaeum variegatum 'Petra': A prevalent variety with oval, green leaves with pronounced veining in pink, red, orange, and yellow hues; can reach 3 to 6 feet tall

Pruning

These plants respond well to trimming, so if your croton plant becomes leggy, prune it back hard at the beginning of the growing season. Remove unhealthy leaves and branches or if you want to maintain a specific shape. Trim just above a node or leaf set. Try not to remove more than a third of the stem at one time. The plant will regrow from the cut portion. If pruning an indoor plant, move it outside once it's been hardened off (gradually introduced to outdoor conditions for a week).

Propagating Croton Plants

Crotons do not grow well from seed, as the plant is unstable and the offspring won't resemble the parent. Instead, propagate croton plants by stem cuttings or "sports." Stem cuttings will encourage new growth and control the size of the plant. In addition, crotons sometimes produce sports, or shoots, that are entirely different from the parent plant. These offshoots can be potted up independently but only cuttings reproduce a plant identical to the parent. However, the process for propagation is the same.

In tropical locales where the temperature remains consistently in the 70 to 80 degree Fahrenheit range, you can propagate croton plants year-round outdoors. Similarly, you can propagate crotons indoors or in a greenhouse if you can maintain the same temperature range.

1. Use sterile pruners, well-draining commercial potting soil (sand, peat moss, and a vermiculite mixture), a growing pot, and rooting hormone (optional). You do not need a pot if you plant directly in the ground in tropical environments.
2. Using sharp, clean pruning shears, cut a 4- to 6-inch stem with the circumference of a pencil at a 45-degree angle right above a leaf node. The cutting should have at least three leaves.
3. Use a rooting hormone on your stem's cut ends to increase the odds of rooting success. Plant the cutting in moistened soil about 1 to 1 1/2 inches deep.
4. Put the plant in a warm, sunny spot away from cold drafts. Keep the soil moist but not soggy. You can enclose the pot in a clear plastic bag to create a greenhouse atmosphere to increase rooting success. After one week, remove the plastic bag.
5. Roots should develop in four weeks. If you notice new growth, the plant has rooted. You can also test rooting by giving the cutting a gentle tug. If it feels taut, it has set roots. Once a plant has rooted, it's ready for transplanting to a larger pot or a spot in the ground.
6. Transfer cuttings indoors anytime but outdoors or in a greenhouse, the temperature must remain consistently around 70 to 80 degrees Fahrenheit for successful transplanting.
   

Potting and Repotting Croton Plants

Repot a young croton every year in the spring or early summer for the first three growing seasons. After that, only repot when you notice roots growing out of the drainage holes or see roots growing at the soil level. Get a container with ample drainage holes. It should be only one size larger than the plant's current container. Put 1 to 2 inches of damp peat-based potting soil into the bottom of the new container.

Remove the plant from its old container by turning the croton on its side and gently sliding it out of its container. Set it in the center of the new pot. Fill in around the roots with potting soil. Water the plant, and add additional soil if needed to bring the soil level to about an inch below the rim of the new container.

Overwintering

Crotons are sensitive to cold weather. If you live in a location that sometimes experiences freezing temperatures or infrequent cold snaps, consider maintaining your plants in pots and bringing them indoors during temps that plunge below 50 degrees Fahrenheit.

To protect in-ground specimens during unexpected cold weather, add about 2 inches of mulch around the base of the plant to insulate the roots. Use gardener’s blankets to keep the frost away. Use stakes to keep the blankets from weighing down the leaves and branches but stake them enough so they do not blow away. These coverings keep in the warmth and protect against ice and harsh winds.

Common Pests & Plant Diseases

Croton is susceptible to a few plant diseases and pests. The insects that like croton plants include mealybugs, spider mites, scales, and thrips. Use pesticides to remove these pests or consider less harsh alternatives, such as horticultural oil or insecticidal soap. If left untreated, leaf growth might become stunted, leaves will drop, and the plant can eventually die. When caring for a croton plant indoors, low humidity can make the plant particularly susceptible to spider mites. Mist your plants daily to help avoid an infestation.

Crown gall is a common bacterial infection that affects crotons. Crown gall appears as thick, swollen growths on the croton's stems and the veins of its leaves. If your plant gets this disease, it's recommended that you pull up the plant, discard it, and sterilize the container and gardening tools. It can spread to other plants and leave a path of destruction in its wake.

Anthracnose is a fungal infection that is sometimes called leaf spot or leaf blight. It makes tan-colored spots on the leaves. Cut off any infected foliage, and avoid letting the leaves touch other plants since its spores can spread. If most of the plant looks affected, treat the plant with a standard copper-based garden fungicide.

How to Get Croton Plants to Bloom

Bloom Months

Croton plants can flower any time of year indoors or outdoors. Though croton plants are known to flower outdoors, don't worry if you never see a bloom on your houseplant. Crotons rarely flower when grown indoors, though it is possible.

What Does a Croton Flower Look and Smell Like?

All crotons are capable of making tight clusters of tiny, pale green star-shaped flowers that blossom from red buds. The flower stem looks like a feathery vine, and the tiny blooms don't have a scent.

How to Encourage More Blooms

Blooms will likely happen when conditions are ideal, such as bright sun, enriched and acidic soil, moist but not soggy soil, and temps in the 70 to 80 degrees Fahrenheit range. Relocating an indoor plant outdoors when the temperatures are warm might spur flower production.

Caring for Croton After It Blooms

Those little blooms can create a mess once they start to fade and drop. For a houseplant, use a disinfected cutting tool to snip off the spent stem of blooms after the flowers fade. It will not hurt the plant.

Common Problems With Croton Plants

A croton plant can be finicky so control its environment as best as possible to help it stay healthy. Watch for these signs of problems to help your croton plant thrive.

Dull Leaf Coloration

Putting the plant in bright light results in vibrant colors but the temperatures must not be sweltering. Summer in tropical zones might be a little too much for some crotons. Reduce or hold off on applying fertilizer during a heatwave or higher temps. Intensely hot days will stress out crotons and can cause graying or flat colors. Fans or air ventilation can cool down the leaves and will help preserve the health of the leaves. Check water levels, and don't let the plant dry out during periods of high heat.

Curling or Rolling Leaves

Leaves can roll or twist when they get large. To fix this, reduce fertilizer. The plant is likely growing too quickly and might need more light to grow properly. Move the plant to a location with more lighting if you can.

Leaf Drop

A well-grown croton plant keeps its leaves down to the soil level. Crotons will drop their leaves at any hint of cool temperatures or cool drafts. Even croton plants outdoors drop leaves after a cold night. Bring in the plant if your plant is in a pot outdoors and temperatures dip below 50 degrees Fahrenheit.

Insect activity can also cause leaves to fall, namely mites and mealybugs. Inspect the undersides of leaves closely for tiny eggs or insects. You'll need to clean off the leaves with insecticidal soap or treat the affected areas with horticultural oil to remove the pests.