Shirley

Bud Architecture and Phenology of the 'Shirley' Tulip

The 'Shirley' Triumph tulip is the result of selective breeding aimed at combining rigid peduncle structure with delicate pigment expression. The key to this variety's success lies in its genetic makeup, which dictates the color shift of the petals throughout the vegetative period. Initially, the bud displays a creamy white tone, which develops a distinct lilac edging as the flower opens and is exposed to solar radiation. This dynamic transition makes 'Shirley' a preferred choice for professional landscaping and forcing.

Technical Profile

• Classification: A member of the Triumph group, providing high resistance to spring temperature fluctuations.
• Morphology: The medium height of the peduncle allows for versatile use in both landscape arrangements and cut flower production.
• Flowering: Mid-season bloom period. The cup maintains a tight structure even under fluctuating thermal conditions.

In practice, this variety is valued for its predictable development. Unlike early-blooming varieties, 'Shirley' demonstrates superior stem strength, which reduces the risk of lodging during windy weather. In temperate climates, the optimal planting window is September through October, when soil temperatures drop to 9–10°C, ensuring robust root establishment without premature sprouting. Agronomists note the variety’s responsiveness to potassium-phosphorus fertilization during the budding phase, which enhances the intensity of the lilac petal margins.