Water deficit can significantly limit the sustainable production of plants, resulting in reduced growth, development, and flowering. Previous studies have shown that the use of biostimulants improves plant stability and promotes growth under low irrigation conditions. The study aims to evaluate the effects of biostimulators on the growth, development and flowering of tuberose (Polianthes tuberosa L.) under water deficit conditions. The experiment was conducted using a completely randomized design with three replications in pots and eight treatments: four irrigation regimes (100%, 80%, 60%, and 40%), and four biostimulant treatments (foliar application of seaweed extract at concentrations of 500, 1000, and 2000 ppm, humic acid at concentrations of 150, 300, and 600 ppm, inoculation of the bed with mycorrhiza, and a control treatment without biostimulators). The length, diameter, fresh and dry weight of the flower pedicel, the number of leaves per plant, the fresh and dry weight of the leaves, stem and root of each plant, as well as the content of photosynthetic pigments, phenol, proline, carbohydrates and flavonoids were measured. The results of this study showed that the growth and development of tuberoses were positively affected by different irrigation levels and biostimulants. The highest morphological characteristics were observed in plants irrigated at 100% field capacity. In contrast, the irrigation regime treatment of 40% of the field capacity combined with 600 mg/liter of humic acid had the most detrimental effect on plant growth indicators. Under stress conditions, the plant also exhibited increased levels of proline, carbohydrates, and flavonoids, which are commonly used as indicators of stress tolerance.