When an orchid’s vibrant display fades, leaving behind a bare stalk, gardeners often wonder how to proceed. This “orchid stem” is technically the flower spike, or inflorescence. How you handle this spent spike is crucial to the plant’s health and its potential for reblooming, especially for the common Phalaenopsis (Moth Orchid). Correctly dealing with the old spike ensures the plant redirects its energy for either a quick secondary bloom or a stronger flowering season in the future.
Understanding the Orchid Spike and Nodes
Before making any cuts, understand the anatomy of the flower spike, which is the long, central stalk from which the flowers emerged. Distinguish between a healthy spike, which remains green and firm, and a dead spike. A dead spike will turn yellow, then brown, and become dry and brittle.
A healthy, green spike contains small, raised, triangular bumps encased in thin, papery sheaths called nodes. These nodes are dormant eyes that contain the potential for new growth, such as a secondary flower spike or occasionally a small new plantlet called a keiki. The location of these nodes dictates where a partial cut should be made to encourage rebloom.
Always sterilize your cutting tool, such as a razor blade or sharp shears, with rubbing alcohol or a bleach solution before touching the plant. This prevents the transmission of fungal or bacterial pathogens into the open wound. Cutting with an unsterilized tool can introduce disease, compromising the orchid’s vascular system.
Choosing the Right Cutting Method
The decision on where to cut the spent spike depends on your priority: speed of rebloom or long-term plant strength. You have three main options, determined by the appearance and health of the spike after the final flower drops.
If the spike is still entirely green and healthy, you can opt for the partial cut to encourage a quick secondary bloom. Locate the second or third node counting up from the base of the plant. Make a clean, precise cut approximately one-half to one inch above the chosen node. This breaks the plant’s apical dominance, signaling the dormant eye to activate and produce a new, shorter flower stalk within eight to twelve weeks.
The partial cut allows for a faster rebloom, but the secondary spike often produces fewer and smaller flowers. This is because the plant uses energy from its reserves rather than building new resources. This method can be taxing on a smaller or less vigorous plant, potentially hindering its overall growth. If the plant has already rebloomed from the same spike, or is small, the full cut is the recommended choice.
The full cut, or cutting the spike completely at the base, encourages a stronger plant and a more robust flowering in the next cycle. Snip the spike down to one or two inches above the base leaves, as close to the plant’s crown as possible without damaging the foliage. Removing the entire spike allows the orchid to conserve energy that would otherwise be spent maintaining the old stalk.
This stored energy is redirected into developing new leaves and roots, which support a large, healthy flower spike in the future. This option means a longer wait time, typically six months to a year for a new spike to emerge. However, the resulting bloom is often larger than a secondary bloom from a partially cut spike. If the spike has already turned yellow or brown, a full cut is necessary, as dead tissue will not rebloom and invites rot or infection.
A third option is to simply leave a green spike alone, especially if the plant is a novelty hybrid that reblooms repeatedly from the tip. The orchid may continue to flower, though the spike will become progressively longer and the flowers smaller. If the spike is still green but does not produce new buds after several weeks, or begins to discolor, switch to the full cut method to begin the plant’s rest period.
Essential Care for Reblooming
After the flower spike has been dealt with, the care regimen shifts to replenishing the plant’s energy and triggering a new spike. Move the orchid to a location that receives brighter, indirect light, such as an east or south-facing window where direct sun is filtered. Adequate light is necessary for photosynthesis, allowing the plant to build the energy reserves needed for the next flowering cycle.
During this rest and growth phase, maintain a consistent watering and feeding schedule. Fertilization should be regular, often weekly or bi-weekly, using a balanced orchid-specific fertilizer diluted to half strength. To encourage new bloom development, some growers switch to a bloom-booster fertilizer with a higher concentration of Phosphorus (e.g., a 10-30-20 NPK ratio) for a few months.
The primary step to initiate a new spike is to introduce a specific temperature fluctuation. Phalaenopsis orchids require a cool period to transition from vegetative growth to blooming. Achieve this by providing a night-time temperature drop, ideally between 55°F and 65°F (10 to 15 degrees cooler than the daytime temperature). Maintaining this temperature differential for two to four weeks usually signals the plant to produce a new flower spike.