A study was conducted at Orman Botanical Garden, Giza, Egypt during 2018 and 2019 seasons to detect the effect of Pb, Cd, and Ni heavy metals in combinations on growth and flowering of Hibiscus rosa-sinensis, L. ornamental plant. Concentrations of Pb + Cd + Ni were 00.00 ppm for control, 500 + 50 + 25 ppm for combination number one (T1) and twice, thrice and four-fold of these concentrations for combinations numbers two (T2), three (T3) and four (T4), respectively.
Results indicated that no mortality was observed among the elemental-polluted plants, although the means of their various vegetative and root growth parameters were progressively decreased with increasing heavy metals concentrations in most cases of both seasons. Thus, the shortest, smallest plants were attained by T4 combination, followed by T3 one. The pollution resistance index (PRI%), was gradually decreased with increasing heavy metals concentrations to be more than 80% in both seasons, even by T4 treatment, pointing to the high ability of such plant to encounter the hazards of toxic metals. Means of flower diameter, flower fresh weight, and concentrations of chlorophyll a, carotenoids and total soluble sugars were decreased, but flower axil length and concentrations of K in the leaves as well as Pb, Cd and Ni in the leaves and roots were progressively increased as a result of the gradual increment of heavy metals, with few exceptions in both seasons.
Accordingly, H.rosa-sinensis plant can be successively used for landscaping of sites polluted with high concentrations of heavy metals.