Grass seed is commonly formulated as either a mixture or a blend. A mixture combines two or more different species of grass. A blend combines two or more cultivars of a single species. Both formulations have their place depending on the site and circumstances. Mixtures have been most common in temperate zone landscapes; single-species plantings have been more common in subtropical and tropical landscapes.
Mixtures sometimes have the disadvantage of variegated color and texture resulting from the different species. They have the advantages of tolerating mixed environmental conditions and resisting devastation by diseases or insects that might wipe out a single species.
Single-species turf plantings offer a more uniform appearance than mixtures, but they are often victims of their own inability to adjust to varied environmental conditions on a site and to resist diseases and insects.
Blends attempt to retain the advantages of both mixtures and singlespecies plantings. If the cultivars are carefully selected, the blend will offer uniform appearance plus environmental adaptability, good resistance to wear, compatible maintenance requirements of all component cultivars, and resistance to pests of the area.