Crotons draw in the houseplant enthusiast with their bright colors and boldly patterned leaves. There are dozens of species and popular croton plant varieties to choose from and they are generally easy to care for. Yet these eye-catching leaves can also bring in more pests than plainer houseplants. Preventing damage, leaf drop, and the spread of disease requires a proactive approach to natural pest control. Make sure your Croton houseplants don’t lose their color or health with these tips for easy pest and disease control.
Dealing With Common Croton Plant Pests & Diseases – The Essentials
Crotons are susceptible to damage from most small insects that can end up indoors, including thrips, aphids, spider mites, and more. They are generally disease resistant but may become infected by powdery mildew or Anthracnose if they are kept too humid.
The Most Common Croton Plant Pests and Diseases (& How to Identify Them)
Croton plants are a tropical group that needs warm temperatures, but they are planted outdoors in Hawaii and Florida. When grown outdoors, they’re prone to several serious pest infestations. Thankfully, only a few pests can affect them when grown indoors as a houseplant instead. The following are the most common pests affecting Croton houseplants.
Spider Mites:
These mites don’t look that much like spiders because they’re a bit too small to see easily. Instead, the name refers to the webs they tend to leave over the soil and along the undersides of plant leaves.
Despite their small size, severe infestations can quickly kill a Croton plant. They need to be treated with a thorough cleaning and use of a pesticide spray or horticultural soap applications weekly. Spider mites spread quickly, so separating houseplants is also key to treatment and control.
Other Mites:
Bright red mites, also known as False Spider Mites, and Two-Spotted Mites can both threaten the Croton plant as well. Yet unlike spider mites, neither of these two pests.
Scale:
One of the best-disguised pests that threaten the health of a Croton plant, scale insects, tend to look more like raised spots on the leaf than insects. Yet that brown or green lump that wasn’t there the day before is actually sucking the sap out of the leaf and weakening the plant.
Scale insects must be removed by hand and then checked for daily. Spraying with pesticides is not a very effective way to treat them, but using the right oils may help keep them away in the first place.
Whitefly:
Whiteflies of all types are a significant pest for Croton plants. There’s even a type of whitefly that specifically targets Croton species and is thus named after the plant. These pests resemble moths as they flutter around plants, but their tiny green or white larvae do the most damage. If whiteflies manage to infest indoor houseplants, they can be hard to treat.
Check for signs of adult flies or their eggs throughout the home, isolating any infested or damaged Croton plants. Insecticides are available in most states that are safe to apply indoors, killing off the larvae and adult whiteflies when they try to feed.
Thrips:
Thrips are tiny, so small they’re hard to spot at all. They’re also often the color of the foliage they feed on to help them hide. You’ll notice patchy, widespread, uneven damage rather than isolated depressions or holes.
If new foliage comes out curly, discolored, or thin, try tapping the Croton over a white sheet of paper. Tiny specks of green or brown around the size of black pepper indicate thrips have infested. Predatory insect controls like beneficial nematodes and mites are generally used in the greenhouse, but you’ll have to stick to horticultural soap and hand-cleaning at home.
Mealybugs:
Small but distinctly fluffy looking, mealybugs are easier to see than many other pests that attack Croton. Yet they’ll still escape your inspections at first, leaving behind damage to the undersides of leaves and stems.
Treating the plant while it only has a few insects attached will increase the chances of success. Even chemical pesticides won’t help if the infestation is severe enough. If the leaves are heavy with mealybugs and their sticky honeydew residues, disposing of the plant may be the only option.
Aphids:
Aphids lead to weak, discolored, and wilting leaves that won’t recover with watering. Aphids are tiny and hard to spot, but they may be visible with a hand magnifying glass if you look along the leaf spines. Cleaning off aphids with horticultural soap and treating the plant with oil can naturally control these pests as long as they’re discovered early.
Croton can also develop several disease problems. Most diseases come with the plant from the nursery, although they may lay dormant until poor care allows them to overwhelm the Croton’s defenses.
Powdery mildew:
Appearing like flour or powdered sugar has been spilled on plant foliage. This fungal disease slowly kills off the infected parts of the Croton. Cut off any infected tissue and let the plant dry out with fresh air to reduce humidity between the leaves. Fungicides can work well, but most must be applied outdoors for safety.
Crown gall:
Caused by a bacterial infection that spreads by using pruning tools, crown gall leads to swollen sections on the leaves, stems, and roots. Destroying the infected plant is the only way to deal with it.
Anthracnose:
If you notice spots on the leaves that are sunken and dark, it could be Anthracnose. This fungal infection means you’re overwatering and misting the plant too much. Let the Croton dry out and use a well-draining mix to ensure fungus levels stay low.
Pesticide and Insecticide Solutions
There are a few different options for dealing with pests and insects. First, check what’s available locally and legal to use in your state. Chemical options vary significantly between states, but almost all areas offer natural treatments like horticultural soap and neem oil.
Horticultural Soap
It may sound silly to wash the leaves and stems of your Croton, but it’s the best way to get rid of most pests without risking damage to the plant. Horticultural soaps penetrate through the shell or exoskeleton of many insect pests to help kill them off directly while remaining relatively inert.
While these soaps are primarily used to treat pest infestations directly, they can also reduce disease risks but removing honeydew and mold growth.
Various Oils
Neem oil is one of the best-known organic pesticides available that’s also known for treating many plant diseases. Croton plants can generally handle their application in diluted sprays or washes.
Other vegetable and essential oils are recommended for specific pest infestations like whiteflies, which can be discouraged with peppermint or rosemary oil.
Isopropyl Alcohol
For stubborn and hard-to-remove insects like scale pests, isopropyl alcohol is a great choice that’s available everywhere. Use a 50% strength product to wipe down the Croton leaves so that honeydew, dust, insects, and more are lifted away. This can be done weekly to reduce disease risk at the same time. There’s no need to rinse the leaves off as long as a proper dilution is used.
Insecticidal Sprays
Thanks to their more rigid leaves, several commercial insecticides are safe for use on Croton plants. However, only a handful of these sprays are recommended for indoor use. You may need to take the Croton outside and keep it there for a few weeks to avoid direct exposure to the chemicals.
How to Use Pesticides & Insecticides for Croton Plants
Target the sprays, soaps, or wipes you choose on the areas showing pest damage signs. But don’t neglect to treat the entire plant, including the soil if the insecticide recommends it. Croton generally needs weekly cleaning and inspection to ensure no signs of insect damage.
Managing Pests & Diseases
Croton plants are generally pest resistant because they have thick, almost leathery leaves. If the plants are attracting pests that suck sap like aphids and mealybugs, they’re likely suffering in other ways from care issues.
Reduce your croton plant watering cycles, offer more sunlight, and balance the soil mix so the plant can resist bugs on its own. Croton often ends up developing diseases if kept too cold in particular. While they don’t like extreme heat, they do want to stay above 60 degrees F at all times (for more, see our in-depth guide to the best locations for Croton plants to thrive in the home or office).
It’s also prudent to fertilize your croton plant monthly in spring through summer each year and pay extra attention to protecting recently propagated croton plants. You’ll also want to prune and repot your croton plant periodically to provide a fresh, nutrient-rich soil base and room for future growth.
Wrap Up
Attractive and generally easy to care for, Croton plants deserve the attention they get for their colorful foliage. Make sure you’re doing all you can for your houseplant by knowing the signs of common pests and diseases that can affect it. By acting quickly at the first sign of damage, you can treat these problems before they overtake your plant’s health.
Andrew is the Editorial Director at Petal Republic. He holds a BSc degree in Plant Sciences and has trained professionally at leading floristry schools in London and Paris. In amongst overseeing a global editorial team, Andrew's a passionate content creator around all things flowers, floral design, gardening, and houseplants.
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