It’s easy to assume that tropical plants want constantly wet soil, but aroids don’t follow that rule. While they come from rainforests, most aren’t growing in soggy ground. Instead, they thrive in humid air and well-draining soil that dries between waterings.
Too much water at the roots leads to rot, while dry air can slow growth and cause leaf damage. Getting the balance right—drier roots, higher humidity—makes all the difference.
Aroids Don’t Grow in Swamps
Philodendrons, Anthuriums, Monstera, and Alocasias come from tropical rainforests, but they aren’t sitting in waterlogged soil. Many are epiphytes or hemiepiphytes, meaning they grow attached to trees rather than rooted in the ground. Even those that grow in soil are often found in loose, decomposing leaf litter that drains quickly and stays aerated.
In the wild, aroids experience:
- Loose and airy soil conditions that prevent water from pooling around the roots
- Frequent but short bursts of rainfall, followed by drying periods
- High humidity that provides constant moisture through the air
Even when it rains daily, their roots aren’t sitting in standing water. Instead, they quickly absorb what they need, and the excess drains away.
Why This Matters Indoors
The biggest difference between aroids in nature and aroids in a home environment is air circulation and soil structure. In their native habitat, constant airflow ensures that moisture evaporates quickly, and microbial activity helps keep the soil well-oxygenated. Indoors, potting soil stays wetter for longer, and without proper aeration, roots can quickly suffocate.
This is why replicating their natural environment indoors—with well-draining soil, occasional drying cycles, and higher humidity—makes all the difference.
Why Too Much Water is a Problem
Overwatering isn’t just about giving a plant too much water—it’s about depriving the roots of oxygen. Healthy plant roots need oxygen to function properly, and when they sit in wet soil for too long, they suffocate.
Here’s what happens when soil stays too wet for too long:
- Air pockets collapse, leading to oxygen deprivation at the roots. Without oxygen, roots struggle to transport nutrients and eventually die.
- Fungi and bacteria thrive in anaerobic conditions, leading to root rot. Pathogens like Pythium and Phytophthora take hold in consistently damp soil.
- Ethylene gas builds up, which accelerates leaf yellowing and overall decline. Ethylene is a stress hormone that signals the plant to drop damaged or struggling leaves.
Aroids naturally regulate their moisture intake, storing water in their thick roots and stems. If they’re forced to sit in constantly wet conditions, their roots begin to break down instead of functioning properly.
Signs of Overwatering
- Yellowing leaves that start at the base of the plant
- Mushy, black, or foul-smelling roots
- Stunted growth despite regular watering
- Soil that takes too long to dry out
Letting the soil dry between waterings isn’t just about preventing root rot—it also encourages the roots to grow deeper and stronger.
Humidity is Just as Important as Watering
Aroids may not want wet roots, but they do need consistent moisture in the air. In nature, many aroids grow in high-humidity environments, where their aerial roots can absorb moisture directly from the air.
Many species develop velamen, a spongy outer layer on their aerial roots that helps them capture humidity. When the air is too dry, these roots dry out and lose function, limiting the plant’s ability to absorb moisture outside of the soil.
What Happens When Humidity is Too Low?
- Leaves curl, brown at the edges, or crisp up as the plant struggles to retain moisture
- New leaves develop misshapen or stuck as they lack the necessary moisture for expansion
- Growth slows down, even when watering is consistent
Most aroids grow best at 50–70% humidity or higher. Some species, like Anthurium clarinervium or Philodendron verrucosum, struggle in typical household humidity and need levels above 60% to thrive.
Why High Humidity Helps Aroids Thrive
- Reduces water loss through transpiration, preventing dehydration
- Supports aerial roots by allowing them to function properly
- Encourages larger, healthier leaves, especially for climbing and vining species
If your aroids are struggling, increasing humidity is often more effective than increasing watering.
How to Balance Watering and Humidity
Rather than watering more frequently, the better approach is to increase humidity while keeping the soil well-aerated and allowing for drying cycles.
Improving Drainage and Preventing Overwatering
- Use a well-draining mix with bark, perlite, and charcoal to keep roots oxygenated. Avoid heavy potting soil that holds excess moisture.
- Let the top few inches of soil dry out before watering again. For most aroids, this means watering when the top 2–3 inches feel dry.
- Choose the right pot size. A pot that’s too large holds extra moisture, increasing the risk of root rot. Aroids often prefer being slightly root-bound.
- Make sure pots have drainage holes. If excess water can’t drain, soil will stay too wet for too long.
Increasing Humidity Without Overwatering
- Use a humidifier to maintain 50–70% humidity, especially in winter when indoor air is drier.
- Cluster plants together to create a natural humidity pocket.
- Place plants on a pebble tray filled with water to add gentle humidity.
- Increase airflow. High humidity without proper ventilation can encourage mold and fungus. A small fan can help keep air circulating.
The Key to Happy Aroids
Aroids are often misunderstood as moisture-loving plants, but what they really need is humid air, steady airflow, and well-aerated soil that dries out between waterings.
Instead of watering frequently, focus on:
- Keeping humidity high so aerial roots can function properly
- Letting soil dry slightly between waterings to prevent root suffocation
- Using well-draining soil to mimic their natural growing conditions
By striking the right balance, aroids grow larger, healthier, and more resilient. When in doubt, humidify the air—not the soil.