Abundance and duration of flowering in Hibiscus paramutabilis × Hibiscus syriacus hybrids

There is no single unified methodology for quantitative measurement for this group of hybrids. In breeding practice, flowering productivity is determined by counting the total number of flowers on a plant during the growing season, and the duration is recorded in days or weeks from the start to the end of flowering.

Hybrids are capable of demonstrating increased productivity compared to parental forms, with the number of flowers directly correlating with crown size. The flowering period inherits the seasonal pattern of Hibiscus syriacus, beginning in late summer and continuing until frost, with breeding efforts aimed at its further extension.

The flowering of these hybrids is strictly linked to the photoperiod and the accumulation of growing degree days. Due to the lack of fixed numerical standards, the evaluation of each new accession is carried out by comparing it with control varieties of Hibiscus syriacus.