Root Rot in Interiorscapes: How to Spot It and Prevent It

Overwatering is the leading cause of root rot in indoor plants—a mistake even experienced plant technicians can make. It often happens when servicing new or unfamiliar accounts or rushing through appointments, which is commonly referred to as the “splash and dash technique” in the interiorscape industry. Overwatering is also more likely on biweekly service schedules, where technicians may overcompensate to keep foliage from drying out between visits. Unfortunately, this can leave the grow pot sitting in water, creating ideal conditions for root rot. Once it takes hold, recovery is difficult, and total plant loss can happen in as little as a few weeks.

I’ve dealt with root rot many times over the years and thought I’d share some tips to help you recognize the warning signs, manage affected plants, and prevent the spread of this damaging disease.

Recognizing Root Rot Symptoms in Indoor Plants

One of the trickiest parts of diagnosing root rot in interiorscapes is that the early signs aren’t always visible. Unlike pests such as mealybugs or scale, root rot begins out of sight, beneath the soil, making it easy to miss in its early stages. Furthermore, symptoms like yellowing or curling leaves are often mistaken for underwatering, nutrient deficiencies, or inadequate sunlight.

But there are some telltale root rot symptoms to watch for. Persistently drenched or soggy soil, a musty or rotting smell, and the presence of fungus gnats are dead giveaways that you’re dealing with root rot. You might also see fungal patches growing on the top of the soil or even on the plant itself. If you suspect an issue, examine the roots directly—healthy roots are white and firm, while rotting roots appear brown and mushy.

Is Root Rot Contagious to Other Indoor Plants?

Fungal spores that cause root rot can be spread through airborne particles, insects, and contaminated gardening tools. While these fungi are naturally present in most soils and typically harmless, they can quickly multiply and attack weakened roots when soil becomes oxygen-deprived due to over-saturation.

Once root rot begins, it spreads rapidly throughout the plant. In atriums or planting beds, the risk of cross-contamination increases significantly since plants often share the same soil. That’s why it’s important to take preventive steps to avoid widespread damage.

How to Prevent Root Rot

Preventing root rot requires a combination of good habits, close observation, and proactive care. Whether you’re maintaining hundreds of plants or just a few installations, the strategies below can help you minimize problems and maintain healthy, long-lasting plants across your interiorscapes.

Monitor Watering Habits and Soil Conditions

Preventing root rot in interiorscapes starts with proper watering practices. When soil becomes oversaturated, oxygen levels drop and root absorption weakens. This creates the perfect environment for fungi to thrive. To avoid these conditions, regularly check soil moisture levels, especially if leaves begin to yellow. Use a moisture meter, soil probe, or wooden stake inserted deep into the pot to check moisture levels below the surface. The common advice to water only when the top inch of soil is dry can be misleading. In fact, I’ve been fooled by this myself more than once. The surface may look dry, but moisture often remains trapped deeper down. This is usually caused by soil compaction, which impedes proper drainage and is a major cause of root rot in indoor plants.

Use Alternative Treatments

While fungicides are a proven and reliable way to prevent and control root rot, there is a more cost-effective alternative—hydrogen peroxide. When diluted—one cup of hydrogen peroxide per gallon of water—it helps boost oxygen levels in the soil and discourages fungal growth. To prevent damage, keep the solution away from the plant’s leaves when watering. Keep in mind that hydrogen peroxide is best for prevention and is likely not strong enough to eliminate an active infection.

For saturated soil, a powdered remedy may be more effective. Interestingly, one such remedy is cinnamon. This common spice has natural antifungal properties and can be dusted over affected areas to help deter root rot.

Stick to the Fundamentals

Finally, don’t overlook the basics. Cleaning and sanitizing gardening tools between uses helps prevent the spread of fungi spores, while well-draining soil and good airflow further reduce the risk of infection. When introducing new plants, inspect the roots to make sure they’re healthy and free of disease.

Stop Root Rot Before It Starts

When you’re responsible for hundreds of plants, preventing root rot is challenging. It takes patience, consistency, and attention to detail. Routine soil checks help detect signs of overwatering early, reducing the risk of root rot and preventing it from spreading. If you notice any symptoms of this disease, don’t wait. Acting quickly can help contain the issue and protect the health of your clients’ plants.