Seedling

A seedling is a young cannabis plant from germination through the first 2–3 weeks of growth, characterized by two embryonic cotyledons followed by serial emergence of true leaves with progressively increasing leaflet counts — beginning with a single unifoliolate pair and advancing through 3-, 5-, 7-, and 9-leaflet palmately compound leaves (Spitzer-Rimon et al. 2019). During the seedling stage the plant is strictly juvenile and non-responsive to floral induction: stipule development at nodes 5–6 marks the end of the juvenile phase, and solitary flower primordia typically appear only at nodes 7–12 (Spitzer-Rimon et al. 2019). Seedlings require moderate light (~200–400 μmol·m⁻²·s⁻¹ PPFD), high humidity (60–70%), and gentle nutrition to avoid damping-off caused by Pythium and Fusarium spp. (Punja et al. 2019). Etymology: Old English sǣd + diminutive -ling. Synonyms: sprout, seed start, juvenile plant, "popped" seed. → See also: Seed, Vegetative.