Vigor — Pelargonium (hybrids)

For interspecific pelargonium hybrids, the vigor index is closely related to the expression of heterosis. In breeding protocols, this trait is assessed by experts or through quantitative indicators of plant height, internode length, and stem thickness in comparison with parental forms or variety series standards.

High vigor determines the garden performance of hybrids, ensuring the ability to fill containers rapidly and providing resilience to climatic stresses. Unlike tall-growing forms, compact types require strict control of agronomic practices to avoid undesirable shoot elongation and loss of decorative quality.