1. Light Requirements

• Ideal Light: Oncidiums need bright, indirect light. Place them near a window with sheer curtains to protect them from direct sunlight.
• Signs of Good Light: If the leaves are a light green, the plant is getting the right amount of light.
• Too Little Light: The leaves may turn yellow, and the plant may become "leggy," with long, sparse growth.
• Too Much Light: The leaves can develop brown or scorched spots. If you notice this, move your plant to a shadier spot.

2. Watering

• Watering Frequency: Water your Oncidium every 5-7 days, or when the top inch of the potting mix feels dry to the touch. It’s important to avoid overwatering, as this can lead to root rot.
• Watering Technique: Water thoroughly until it runs out of the drainage holes. Always empty the saucer under the pot to avoid water sitting at the bottom, which can cause root rot.
• Signs of Overwatering: Yellowing leaves and a mushy, rotten smell in the soil.
• Humidity: Oncidiums prefer humidity between 40-70%. If your home is dry, use a humidity tray or place a room humidifier nearby.

3. Temperature

• Ideal Temperature: Oncidium orchids thrive in temperatures between 70-85°F (21-29°C) during the day and 55-65°F (13-18°C) at night.
• Avoid: Exposure to cold drafts or sudden temperature fluctuations, which can stress the plant.

4. Fertilizing

• Fertilizer Type: Use a balanced, water-soluble orchid fertilizer (e.g., 30-10-10, or an orchid-specific fertilizer) or a fertilizer with a higher phosphorus ratio during blooming time.
• Fertilizing Schedule: Fertilize every 2 weeks during the growing season (spring and summer) and once a month during the dormant period (fall and winter).
• Dilution: Always dilute the fertilizer to half strength to avoid overfeeding the plant, which can cause root burn.

5. Potting and Repotting

• Potting Medium: Use a well-draining orchid bark mix, sphagnum moss, or a commercial orchid mix. Avoid regular potting soil, as it doesn’t provide the drainage needed for orchids.
• Repotting Frequency: Repot your Oncidium every 1-2 years to refresh the potting medium and promote healthy root growth. Repotting is also recommended if the roots have outgrown the pot or if the medium has decomposed.
• Repotting Tips: When repotting, carefully remove the plant from the pot, trim any dead or rotten roots, and place it in a new pot with fresh potting mix. Ensure the plant is positioned securely in the pot.