Turveperliitti

Turveperliitti is a Finnish term for a horticultural growing medium that combines peat (turve) with expanded perlite (perliitti). The peat provides moisture retention and some nutrients, while the perlite adds aeration and drainage by creating air-filled pores. The resulting substrate is lightweight and highly porous, making it suitable for seedling production, plug trays, and greenhouse cultivation.

Composition and production

Typical formulations blend milled peat with expanded perlite in varying proportions, with perlite generally accounting for a portion of the mix by volume. Additional components such as composted bark or mineral amendments may be included. The pH of peat is typically acidic, and some products are adjusted with lime or other agents to suit specific crops. The exact mix can vary between manufacturers and intended uses.

Uses

Turveperliitti is used as a growing medium for starting seeds, rooting cuttings, and growing young plants in pots or trays. It can be sold as a ready-to-use substrate or used as a component in custom potting mixes. Its lightness and good drainage help reduce waterlogging and support early root development.

Advantages and considerations

Advantages include low bulk density, strong porosity, and good water-holding capacity, which support young plants and fast establishment. Disadvantages include relatively low inherent nutrient content, potential for peat decomposition over time, and sustainability concerns related to peat harvesting. Consequently, there is ongoing demand for peat-free or peat-reduced media, using alternatives such as coir, wood fiber, or mineral substrates.

See also: peat, perlite, horticultural substrate, peat-free growing media.