GLADIOULUS ITALICUS "BYZANTINUS" (6 ratings) Gladioulus Italicus Byzantinus | Pack of 10 bulbs | Good quality bulbs to brighten up your spring garden. €3.99 Out of stock. 0 in your basket View Basket Checkout Byzantinus. Eye-catching violet red flowers on tall stems. RHS Award winner Flowering Time: June Flowering Height: 75cm/30 inches Planting Depth: 8cm/3 inches Planting Distance: 10cm/4 inches Planting Time: August Onwards Soil/Position: Gladiolus like full sun and well-drained soil enriched with humus such as leaf mould or compost. Application: Great for naturalising in borders and cut flowers Expert Tip: Good for naturalising (flowers for year after year).