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In vitro tulip embryos have an active shoot-forming capacity (up to 320 neoformations per embryo, for a 20-month period) when cultured, at a temperature of 20–24 °C under a 16-h day length (4000 lx), with growth regulators: naphthalene-acetic acid (0.5 mg ∙ L−1) and benzylaminopurine (1 mg L−1) or kinetin (0.5 mg L−1) or isopentenyladenine (1 mg L−1). Repeated fragmentations improve or maintain shoot-forming ability. Nevertheless, an important genotypic effect is observed. When neoformations are subjected to a cold treatment of at least 40 days at 6 °C under short days (8 h, 2500 lx) and then transferred at 24 °C under long days (16 h, 800 lx), they produce numerous functional bulblets.