The most common houseplant orchid, the Phalaenopsis or Moth Orchid, offers a long-lasting bloom, but getting it to flower again presents a frequent challenge for many owners. The plant will not bloom continuously year-round; instead, re-flowering is a cyclical process that requires the grower to provide a specific environmental trigger. By understanding the plant’s needs and intervening at the right time, you can successfully encourage the development of a new flower spike.
Essential Environmental Conditions
The foundation for a re-blooming orchid is a healthy plant, which depends on receiving bright, indirect light. An ideal placement is an east-facing window, or a shaded south or west window, to provide the necessary light intensity without scorching the leaves. When the leaves are a medium, light green color, the plant is receiving sufficient light; excessively dark green leaves suggest light levels are too low to support the energy-intensive process of blooming.
Proper watering involves thoroughly drenching the potting medium and then allowing it to become nearly dry before watering again. A good method is to soak the pot in a container of water for several minutes, allowing the bark to absorb moisture, then letting it drain completely. You can tell the plant needs water when the aerial roots visible in the pot turn from a healthy pale green to a dull, silvery white.
Because Phalaenopsis orchids are tropical epiphytes, they appreciate a higher level of atmospheric moisture than is typically found in a home. The ideal humidity range is between 50% and 70%, though they can tolerate levels as low as 40%. Placing the orchid on a humidity tray filled with pebbles and water, ensuring the pot bottom does not touch the water, helps to create a beneficial microclimate around the plant.
Using Temperature Shifts to Initiate Spiking
Once the orchid is healthy and has finished its previous blooming cycle, a temperature shift acts as the primary signal to initiate a new flower spike. While a significant difference between day and night temperatures was traditionally thought necessary, studies suggest the key is a sustained reduction in the average growing temperature.
To trigger a new spike, the plant should be exposed to an average temperature drop of about 10 to 15 degrees Fahrenheit below its normal growing temperature. This means maintaining cooler conditions, ideally with nighttime temperatures consistently falling between 55°F and 65°F. This cooler period should be maintained for a duration of approximately two to four weeks.
To achieve this, move the orchid to a cooler room or place it near a window at night during the autumn months. It is important to ensure the plant is not exposed to cold drafts, which can cause chilling injury or bud drop. Once a new flower spike is visibly developing, the plant can be returned to its normal, warmer daytime environment.
Nutrient Requirements During the Bloom Cycle
Fertilization is an ongoing part of orchid care, but the composition of the fertilizer is often considered when encouraging a bloom. Traditionally, growers switch from a high-nitrogen formula, which promotes vegetative growth, to a high-phosphorus formula, often called a “bloom booster,” once the spiking process begins.
However, some scientific findings indicate that a balanced fertilizer, such as a 20-20-20 formula, provides adequate nutrients for flowering, especially if the plant has been consistently fed during its growth phase. Research suggests that the plant stores necessary phosphorus in its tissues, and a higher nitrogen ratio can even lead to more flowers. The most important rule remains to feed weakly (using a highly diluted solution) but frequently, such as once per week.
Because chemical fertilizers contain mineral salts, they can build up in the potting medium over time, potentially damaging roots and leaf tips. To prevent this accumulation, it is important to flush the pot thoroughly with plain water once a month. This action washes away excess salts and maintains a healthy root environment.
Care and Maintenance of the Flower Spike
Once the new spike emerges, it will initially look like a smooth green protrusion, growing upward from the base of the plant. As the spike lengthens and the buds begin to swell, it becomes susceptible to breakage. To prevent damage, a thin support stake—made of bamboo or metal—should be inserted into the pot and the spike gently secured to it using small, loose clips.
The spike should be staked early in its development before it hardens, allowing you to guide its growth without snapping the tender tissue. Once the flowers have completely dropped from the stem, you have a choice regarding the spent spike to encourage the next bloom. One option is to cut the spike back to about half an inch above the second triangular node, or joint, counting up from the base of the plant.
Cutting above a node encourages the plant to produce a secondary, but often smaller, spike from that joint for a quicker re-bloom. If the entire spike begins to turn yellow or brown, or if you prefer to redirect the plant’s energy toward developing stronger roots and leaves, the stem should be cut off completely near the base. This method delays the next bloom but encourages a more robust flower spike in the following cycle.