Orchid Fertilizing Guide: When, How, and What to Use

Fertilizing orchids is one of the most overlooked aspects of orchid care — but it's key to getting your orchid to rebloom and stay healthy long-term. Here's a complete guide to feeding your orchids correctly.

Do Orchids Need Fertilizer?

Yes. In their natural habitat, orchids get nutrients from rainwater, decomposing organic matter, and the bark of trees they grow on. In our homes, potting bark provides very little nutrition, so regular fertilizing is essential.

What Fertilizer to Use

Balanced Fertilizer (20-20-20)

A balanced fertilizer is ideal for general orchid feeding during the growing season. It supports healthy leaf and root growth.

Bloom Booster (10-30-20)

In late summer to fall, switch to a high-phosphorus fertilizer to encourage blooming and flower spike development.

Orchid-Specific Fertilizers

Look for urea-free formulas — urea requires soil bacteria to convert it to a usable form, and orchid bark doesn't have enough bacteria to do this efficiently.

How Often to Fertilize

Follow the popular orchid grower's mantra: Weekly, weakly. Fertilize every week at quarter strength rather than full strength monthly.

• Growing season (spring-summer): Every 1-2 weeks at quarter to half strength
• Fall: Switch to bloom booster, every 2 weeks
• Winter: Reduce to once a month or stop entirely

How to Fertilize Orchids

1. Water the orchid first with plain water before fertilizing.
2. Mix fertilizer to quarter or half the recommended strength.
3. Pour the diluted fertilizer over the bark mix, allowing it to drain completely.
4. Once a month, flush the bark with plain water to prevent salt buildup.

Signs of Over-Fertilizing

• Brown leaf tips or edges
• White salt crust on the bark or pot edges
• Root burn (brown, crispy root tips)

Signs of Under-Fertilizing

• Pale, yellowing leaves
• Slow or no growth
• Failure to rebloom despite good light and watering

Key Tips

• Always water before fertilizing
• Use urea-free fertilizer for best results
• Flush with plain water monthly to prevent salt buildup
• Switch to bloom booster in fall to encourage reblooming