Strelitzia reginae is an important cut flower native to South Africa. The effect of silicon and gibberellic acidwith sucrose as conditioners on the post-harvest quality of Strelitzia cut flowers was investigated. Inflorescence shoots were conditioned for 24 hours in: water solutions of Actisil 0.2% or gibberellic acid (GA3) – 200 mg∙dm–3 + sucrose 10% or distilled water (control). The shoots were then placed in distilled water or Chrysal Clear Professional 2 (10%). It was found that GA3 + sucrose and Actisil increased the size of orange sepals and blue petals when after conditioning, the shoots were placed in water or Chrysal. Conditioning in Actisil and storage in Chrysal increased the value of mechanical parameters of flowers, leading to greater flexibility and lower susceptibility to fracture. Conditioning the shoots in Actisil and keeping them in Chrysal extended the life of flowers by 2 days.