When an orchid grower notices a small, green nub emerging, it is a positive sign of health, indicating the plant has sufficient energy to expand its structure. However, proper care depends entirely on whether the growth is a potential flower spike, a new plantlet (keiki), or an aerial root. Accurate identification of these three distinct types of growth is necessary to ensure the orchid’s long-term health and successful development.
Identifying the Flower Spike
The flower spike is often the most hoped-for growth, promising the dramatic blooms for which orchids are known. This nascent spike usually emerges from the stem between the leaves, often underneath the second or third leaf from the top. A key visual cue is the shape of the tip, which appears blunt or slightly rounded, often described as resembling a tiny mitten or a closed fist.
As the spike elongates, it retains its green color and develops small, triangular structures called bracts or nodes. These nodes are where individual flower buds or secondary flower branches will eventually form. Spikes grow rapidly and consistently orient themselves toward the strongest light source, which helps to distinguish them from the haphazard growth pattern of a root. Temperature plays a significant role, as a drop in temperature, especially at night, often triggers Phalaenopsis orchids to initiate a flower spike, which typically takes two to four months to fully bloom.
Identifying the Keiki (Plantlet)
The term “keiki” is Hawaiian for “baby” or “child,” referring to a small, genetically identical plantlet growing directly from the mother orchid. A keiki usually appears at a node along an existing flower stem, or sometimes emerges from the base of the plant, known as a basal keiki. While a keiki may initially be mistaken for a flower spike, its development quickly diverges from a floral structure.
Instead of forming a blunt, mitten-shaped tip, the keiki rapidly differentiates into miniature leaves resembling the parent plant’s foliage. Following leaf development, the plantlet produces its own aerial roots, essential for its independent life. The presence of these tiny leaves and subsequent roots confirms the growth is a keiki, representing asexual propagation rather than a bloom. While keikis are a natural method of reproduction, their appearance can sometimes indicate the parent plant is under stress and attempting to clone itself.
Identifying the Aerial Root
Aerial roots are the easiest of the three growth types to identify due to their distinct morphology and growth habit. Orchids are epiphytes, meaning they naturally grow on other plants like tree branches, using their roots for anchorage and the absorption of moisture and nutrients from the air. This explains why roots often grow outside the pot, hence the name “aerial roots.”
The tip of a healthy aerial root is rounded, smooth, and often capped with a bright color (green, purple, or red), depending on the plant’s pigmentation. The main body of the root is covered in velamen, a spongy, protective layer that appears silvery-white or gray when dry. When watered, the velamen rapidly absorbs moisture and turns a vibrant green, visible through the translucent outer layer. Unlike a flower spike that grows toward the light, an aerial root grows randomly, often downward or outwardly, and never develops the nodes or flattened tip characteristic of a spike.
Care Instructions Based on New Growth Type
Once the type of growth is confirmed, specific adjustments to the orchid’s care regimen should be implemented. For a flower spike, the focus shifts to supporting the bloom cycle by increasing watering frequency and using a diluted, balanced fertilizer to sustain the energy-intensive flowering process. The lengthening spike should be gently guided and secured to a stake with soft ties to prevent damage and encourage a graceful display.
If the new growth is identified as a keiki, it must remain attached to the mother plant until it is mature enough to survive independently. Wait until the keiki has developed at least two or three leaves and roots that are one to two inches long. At this point, the plantlet can be carefully removed with a sterile tool and potted separately. Apply an antifungal, such as cinnamon, to the cut surfaces of both the mother and the keiki.
For aerial roots, the primary instruction is to leave them alone, as trimming healthy roots reduces the plant’s ability to photosynthesize and absorb water. The silvery appearance of dry velamen indicates the need for watering. However, the roots should not be buried into the potting medium, as they are adapted to open air. Ensuring adequate humidity around the plant helps the aerial roots function effectively and remain plump and healthy.