When buying lawn seed for these elevations, the seed is often packaged as a mixture. The mixture includes two or more different species of grass. The most common mixture for high elevation locations include a three-way mixture of KBG, perennial ryegrass and fine leaf fescue.
Tall fescue is included in mixtures only in special cases and is best planted alone.
The reason that these species are mixed together is that each grass plays a special part in the course of the life of the lawn. The intention is as follows. The KBG is intended to be the permanent and predominate species. Rhizomes allow the turf to become thick, crowding out weeds and serving as a growing point for the grass to regrow when it is injured, diseased or undergoes long periods of drought. The quick germination and emergence of perennial ryegrass binds the soil and makes a quick and thin lawn while the other grasses germinate slower and grow lazily at first.