When should you avoid fertilizing orchids?
Written by
Kiana Okafor
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.An awareness of the times to abstain from fertilizing orchids allows for greater saving potential than any feeding cycle. This was learned the hard way, having lost a favorite cattleya to salt toxicity while in dormancy. Like most plants, orchids must have rest periods, during which time they will suffer if nutrients are not withheld. The awareness of the critical times significantly improves the saving potential of orchids.
Dormancy represents the first of the three pause periods. Deciduous orchids, such as dendrobiums, drop leaves in response to shorter daylight hours, indicating continued rest. Metabolism decreases by 80% during dormancy. Fertilizing at this time encourages the orchid to produce weak and green growth, rather than flower spikes. One rule of thumb is to wait until new pseudobulbs appear to fertilize. If no new green growth is visible, do not fertilize.
Dormancy Signs
- Leaf drop in deciduous varieties
- No new root or shoot development
- Pseudobulb shrinkage in sympodial types
- Complete halt in vegetative growth
Environmental Stress
- Temperatures exceeding 90°F (32°C)
- Humidity below 40% for over 48 hours
- Intense direct sunlight causing leaf scorch
- Drought conditions with wrinkled pseudobulbs
Recovery Phases
- Four weeks post-repotting
- Six weeks after pest infestation
- During active fungal/bacterial treatment
- Root system regeneration phases
Air temperature over 90°F (32°C) can put your plant's flowering cycle at risk. The roots stop absorbing liquids, but salts build up. The plant's velamen becomes damaged and is not recoverable. In heatwaves, I mold water and use no other inputs. Resume nutrients slowly once it cools back in the 70s consistently.
After remediation, orchids also require nutrient breaks. If it has been repotted, allow the roots an additional four weeks for proper recovery/re-rooting. After a pest infestation, allow six weeks to recover. Stressed orchids exhibit fertilizer intolerance, as evidenced by yellowing leaves and black tips on the root system. Always allow more time for hydration and less for nutrients and amendments.
Look for visual signs indicating that feeding can resume. New root tips are white and firm. Plump pseudobulbs indicate that the orchid is ready to resume feeding. If flower spikes begin to emerge, the orchid is starting to grow again (indicating active growth). Use quarter-strength solutions again to start. Your patience during periods of pause will benefit you in the long run, enabling you to manage stronger and healthier orchids.
Read the full article: How to Fertilize Orchids: Ultimate Guide
