In Poland, zeolites are relatively rare substrates. These are natural aluminosilicate minerals with excellent sorptive and iron exchange properties. Mixing substrates with zeolite improved the physical and chemical properties of the media such as total porosity or water holding capacity. The research was aimed at assessing the usefulness of zeolite in the production of Catharanthus roseus and Gazania rigens var. rigens seedlings. For sowing the following substrates were used: 1. deacidified peat, 2. substrate ready for sowing AURA of Hollas, 3. peat + fine zeolite 1:1, 4. peat + fine zeolite 3:1, 5. peat + coarse zeolite 1:1, 6. peat + coarse zeolite 3:1. The Azofoska fertiliser was added to all substrates at a dose of 2 g∙dm^-3. At the second stage of the experiment, seedlings from each variant were planted in three substrates including: I. deacidified peat, II. peat with the addition of 20% fine zeolite, III. peat with the addition of 20% coarse zeolite. Addition of zeolite to the substrate for sowing improves seedling root development, while limiting the growth of shoots of Gazania rigens var. rigens. Plants of Gazania sown on substrates with zeolite – regardless of the type of substrate used for further cultivation – produce more flower buds than plants from other substrates. The least favorable for the growth and flowering Catharanthus roseus effect the substrate with fine zeolite in an amount of 20%; plants have been lower had fewer leaves, and definitely less flourish.

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