Dicas fáceis para combater fungos nas orquídeas.

Easy Tips to Fight Fungi on Orchids (and Prevent Them)

Why Fungus Appears (Most Common Causes)

• Wounds/injuries to the plant create entry points (e.g., pot edges/support rubbing the leaves, punctures).

• Pests (like mealybugs and mites) damage tissue and open spots for fungal growth.

• Sunburn can leave a mark that later becomes an entry point.
• Overly wet conditions (high humidity, staying wet too long, or cold wetness) increase the risk.

Act Fast: Identify and Isolate

• Treat any dark spot early—especially if you see a dark spot surrounded by yellowish tissue (fungus).
• If you notice a large, soft, watery black spot, it may be black rot:
  • Separate it immediately from other orchids, because it spreads quickly.

Climate Matters (Prevention Is Environment-First)

• Low humidity climates tend to have fewer serious issues (the speaker says they rarely see black rot/dry issues).
• Very humid/rainy climates require regular prevention, at least once a month.
• Watering habits are the #1 factor:
  • Wait for the plant/substrate to dry before watering again.
  • Match your watering schedule to your climate (some humid-climate growers water far less often—e.g., every ~15 days).

Watering Rules to Reduce Fungal Outbreaks

• Don’t wet the orchid leaves as much as possible.
• If a fungal area is present, avoid getting that leaf area wet.
• If leaves are under/behind other plants and water drips onto them, reposition/move the plant to prevent wetting.
• Be extra careful in cold conditions:
  • If leaves get wet and can’t dry before temperatures drop, fungal risk rises.

Improve Airflow (Circulation/Ventilation, Not Just “Wind”)

• Leave space between plants for air circulation.
• Use an orchid setup that dries faster:
  • Pots with more holes and open cachepots improve ventilation.
• Avoid placing orchids in tight hallway spots with constant airflow.

---

Treatment Options (More “Natural/Home-Made” Approach)

1) Propolis Extract (Spot Treatment + Paste)

What It Is

• Use propolis extract purchased from a pharmacy (not a throat-spray product).
• Any strength is acceptable as long as the label says “propolis extract.”

How to Use

• Direct drip method (for small spots):
  • Drip directly onto the stain.
  • Don’t immediately wash/rinse it off; avoid wetting the leaf right away.
  • Do not dilute with water.
• Propolis + ground cinnamon paste (for better sealing/protection):
  • Mix a tiny amount of ground cinnamon with a little propolis extract until it forms a paste.
  • Apply a small amount directly on the affected spot.

How Long to Leave It

• Leave it on the lesion like an ointment—do not rinse it off.

Re-treatment Frequency

• If the fungus persists or spreads to new areas:
  • apply once a week or every 3 days.

---

2) Hydrogen Peroxide (Prevention + Control)

Mixing Ratio

• 1 liter of water + 4 tablespoons hydrogen peroxide
  • or 4 capfuls (described as 10-volume hydrogen peroxide).

When/How to Apply

• Don’t apply in direct sunshine on the orchids.
  • The speaker recommends late afternoon (even filtered light is okay).
• Don’t rinse it after applying—leave it to work.
• After application, you can water the next day; the speaker says it’s fine even if leaves get wet then.

Use Case: Whole-House Prevention

• They may spray the orchid area first, then (1–2 days later) apply propolis only where needed.

Bigger/Inside-Plant Infection Approach

• For fungus starting down near the rhizome/pseudobulb:
  • immerse the orchid (fits whole pot) in hydrogen peroxide solution
  • leave for 15–20 minutes
• The speaker also says they use this method for slugs/snails.

---

If It’s Getting Out of Control

• For more serious fungi (the speaker mentions types like dry rot/black rot as needing escalation):
  • seek help from an agronomist
  • visit an agricultural supply store and ask what fungicide fits
• If many orchids are affected, spot-by-spot propolis may be impractical.

---

Notable Orchids, Locations, Products, and References

• Orchids referenced: Phalaenopsis; Denphal/“Denfal” orchids from a cousin.
• Notable fungal conditions mentioned: black rot, dry rot, and “dry cinnamon fungus” (noted as a different/more complex case).
• Products:
  • Propolis extract (pharmacy/online; label must say “extract of propolis” / “propolis extract”)
  • Hydrogen peroxide 10-volume
• Setup/location cues: orchid “orchidarium” setup, open cachepots, and pots with more holes for airflow.