This hot-growing species has been a break-through in breeding many modern yellow hybrids, notably in 1950s and 60s. Its progeny carries bright yellow colour, longevity and sweet fragrance of their flowers. However, due to hot-growing, natural environment, its hybrids are less cold-tolerant that the blue-flowered species.
Position
Max Height
1-1.5 metres
Max Spread
0.5-1 metres