DIY Aroid Soil Mix: A Balanced Recipe for Healthy Tropical Plants

When it comes to growing tropical plants, soil is not just a medium, it’s a living environment. The right mix supports roots, manages moisture, and creates stability over time. The wrong one suffocates roots, holds water too long, or breaks down too quickly.

Welcome to the garden, young Cormie 🌿

Let’s talk soil with intention.

This DIY aroid mix is the foundation I use for Alocasia, Monstera, Philodendron, Hoya, Anthurium, and many other tropical plants. It’s designed to be adaptable, not rigid because no two homes, climates, or growing conditions are exactly the same.

 

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What This Aroid Mix Is For (And Why Density Matters)

This mix works best for tropical plants that naturally grow in loose, organic, oxygen-rich environments, often climbing trees or spreading through forest floors rather than sitting in compact soil.

I regularly use this mix for:

• Alocasia
• Monstera
• Philodendron
• Hoya
• Anthurium
• Many other tropical houseplants

That said, density matters more than the ingredient list itself.

Some plants thrive in a chunkier, faster-draining mix:

• Monstera
• Mature Anthurium
• Larger Philodendron

Others prefer a mix that holds slightly more moisture:

• Begonias
• Younger Anthurium

• Certain Alocasia

This recipe is a base system, not a fixed rule. You will adjust it depending on:

• Pot type (plastic, ceramic, self-watering)
• Light levels
• Humidity
• Whether plants live indoors or outdoors

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Miyagi’s DIY Aroid Mix Recipe (Base Formula)

This is my go-to starting ratio:

• Coco Coir – ~25%
  Coco coir provides a soft, fibrous base that holds moisture evenly without becoming muddy. Unlike peat, it resists compaction and keeps roots oxygenated over time.
• Coco Chips – ~25%
  Coco chips add structure. They create air pockets, slow down soil breakdown, and help roots anchor naturally. This is especially important for climbing aroids.
• Perlite #3 or #4 – ~25%
  Perlite improves drainage and airflow. I use #4 most of the time because it stays chunkier longer and doesn’t collapse as easily.
• Activated Charcoal (chunky) – ~5–10%
  Charcoal helps absorb impurities, manage odors, and support long-term soil health. Think of it as a quiet stabilizer rather than a nutrient source.
• Orchid Bark – ~5–10%
  Orchid bark mimics the woody debris tropical plants grow around in nature. It improves airflow and gives roots something to grip as they mature.
• Compost – ~5%
  I use high-quality compost instead of worm castings for broader nutrient diversity and microbial support. I currently work with O-Town Compost. Actually, we sell their compost in the shop (LINK COMING SOON)

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This combination creates a mix that:

• Drains efficiently
• Retains moisture without staying soggy
• Does not become fully compact
• Works well in self-watering systems

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Preparing Each Ingredient (Best Practices)

Most soil issues don’t come from bad ingredients. They come from skipping preparation.

 

Coco Coir & Coco Chips (Brick Preparation)

Coco products often arrive compressed and must be rinsed before use.

Why this matters:
Coco can retain salts from processing. If used straight from the brick, those salts can stress roots and slow growth.

My process:

1. Fully hydrate the brick with warm water
2. Break it apart by hand
3. Rinse thoroughly until runoff is mostly clear
4. Drain excess water before mixing

🧠 Sensei Tip:
Coco should feel evenly moist, not dripping wet, before it goes into your mix.

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Perlite (Handling & Safety)

Perlite is essential for airflow, but it comes with fine dust that gets released as you open the container or move it.

I now handle perlite outdoors only. If possible, wear a mask or a bandana covering your nose and mouth.

Best practices:

• Slightly dampen perlite before mixing
• Avoid breathing dust directly
• Use #4 for chunkier mixes, #3 for finer blends

Your lungs will thank you and your plants will too.

 

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Activated Charcoal

Activated charcoal does not feed plants, but it supports balance. It helps reduce buildup, improves longevity of the mix, and keeps things fresher over time.

Always use chunky charcoal, not powder, and distribute it evenly.

🧠 Sensei Tip:

Use charcoal at the top 1in or your pots. It helps to prevent fungus gnats crawling into your soil and prevents fungus in general. Plus, it looks sleek and gives presence to your plant.

 

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Orchid Bark

Orchid bark provides long-term structure. It’s especially useful for:

• Plants on moss poles
• Larger aroids

• Outdoor tropicals exposed to rain

If your plant tends to stay wet too long, increasing bark content can help.

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Compost vs Worm Castings

I have transitioned from worm castings to compost because:

• Compost offers a broader nutrient profile
• It breaks down more gradually
• It supports microbial diversity

⚠️ Important note:
If you’re starting with a nutrient-rich soil like Fox Farm Ocean Forest or Forbidden Cereal Aroid Mix, do not add compost. Pre-Made Soils, many times, already contain nutrients. Therefore,  adding compost on top can cause nutrient burn.

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Shortcut Option: Using Pre-Made Soil as a Base

If mixing everything from scratch feels like too much, this is a solid alternative:

Start with:

• Fox Farm Ocean Forest
• Forbidden Cereal Soil 
  

Then amend with:

• Chunky perlite
• Activated charcoal
• Orchid bark

Skip compost in this case.

This hybrid method works especially well for beginners who want consistency without fully DIY mixing.

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Optional Ingredients & Substitutions

Depending on availability or preference, you can also use:

• LECA – I often replace orchid bark with LECA when it’s readily available
• Pumice – Excellent long-term aeration
• Calcined clay – Improves structure and moisture balance
• Worm castings – Can replace compost if preferred

Each ingredient changes how the mix behaves. Start simple and add complexity only when needed.

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Climate, Growth Zones & Placement Matter

I grow in Florida, USDA Zone 10a, warm, humid, and bright for most of the year. Therefore, the environment works to grow a large selection of plants.

Your environment may be very different.

FIND YOUR GROWTH ZONE IN THE US HERE

Indoor Growing

• Lower airflow
• More stable temperatures
• Often requires extra drainage

Outdoor Growing

• Rain exposure
• Higher humidity
• Faster breakdown of organic materials

Before settling on a mix, consider:

• Indoor vs outdoor placement
• Seasonal temperature swings
• Humidity levels
• Pot type

Adjust density accordingly. There is no universal recipe, only thoughtful adaptation.

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Self-Watering Compatibility

This aroid mix works very well with self-watering planters when balanced correctly.

For best results:

• Avoid heavy compost layers
• Maintain even particle distribution
• Ensure the mix can wick without staying saturated

📌 A dedicated self-watering guide will be linked here soon.

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Final Thoughts from Miyagi

Soil isn’t about perfection.
It’s about understanding systems and responding with intention.

Start with a balanced base, observe your plants, and adjust slowly. That’s how confidence grows in both plants and people.

Happy mixing,
Miyagi 🌱