Phalaenopsis Node Activity and Reblooming Strategies

Understanding Phalaenopsis Flower Spike Nodes

Mark bought Phalaenopsis at Lowe's 9 days ago (6 blooms). Blooms fading 4 days ago. Nursery said pinch white thin bloom stems near main stem—did, may rebloom. No rebloom at pinch points yet. Further down main stem: 4 swollen nodes equally spaced to base. Upper two swollen, purplish paper-thin sheathing, green BB-sized bump under sheath on node (hard like pimple head). Lower two nodes purplish-brown sheath, less swollen, flat, nothing green. Asks: upper nodes more energetic? Does orchid send nourishment upward? Cooler air shock to bloom? Ice gel pack near base or node to induce earlier bloom?

Expert Response

Mark, no good explanation why upper nodes more likely to produce branches. Nature may select upper flowers for pollinator visibility. Growth hormones in upper node(s) produce inhibitors for lower nodes—conserves energy, maximizes pollination. Remove spike portion above uppermost active node to prevent inhibition. Generally cut green spike above 3rd node. Any node can produce branch or keiki. Keikis more likely under low light; branches under high light. Bracts protect meristematic tissue. Cold as stressor may induce flowering as survival mechanism—not best way (may affect health, root rot, mesophyll collapse). Commercial growers retrieve plants after flowering, cut green spikes above node for second flowering same year/temp. Bright light induces/enhances flowering. Most Phalaenopsis flower in spring as day length increases—day length role. Consider repotting in fir-bark mix after flowering. Judge by leaf health. Plants in moss/degraded mix decline fast; by leaf yellowing/drooping, root damage done. Bought many from Lowe's/Home Depot—no consistency in mix. Home Depot nursery person said supplier told water twice daily. Nurseries want plants out fast, not long-term care.