Double flowers in Impatiens walleriana

The expression of doubleness in Impatiens walleriana depends on environmental conditions, including light intensity and temperature regime. In breeding, professional series such as Fiesta are evaluated based on criteria of petal layering and the flower's ability to maintain a rounded shape upon opening.

Cultivation of double-flowered forms carries the risk of incomplete bud opening. There is also a correlation between doubleness and plant habit: double lines are more prone to stem stretching, which requires control of nitrogen nutrition balance. An important agrotechnical indicator of a variety is its ability to self-clean from withered double corollas.