Performance Without Irrigation
Tall Fescues, like most grasses, prefer to have adequate moisture, but Tall Fescue can persist and evade dormancy far longer than other turfgrasses thanks to its ability to root very deeply, allowing it to find water during times of drought. Tall Fescues are very persistent even under very dry condition. Newer varieties with Endophyte Enhancement provide resistance to surface feeding insects, which has proven to be of great benefit during periods of drought stress.
Perennial Ryegrasses are not highly drought tolerant. They will go into dormancy under drought stress. Endophyte enhancement can aide in performance during dryer periods, as this feature prevents damage from surface feeding insects that can amplify the effects of drought in dryer periods. Under traffic, irrigation is required to prevent stress in order for this highly wear tolerant specie to perform at a high level.
Fine Fescues are highly drought tolerant because they survive under dormancy, greening up again when moisture becomes available. In low maintenance situations, they have the ability to be very persistent because of this ability. In situations where the appearance of dormant turf is not desirable, irrigation can be supplied. They do not like wet soils so care should be taken only to apply what is needed.
Kentucky Bluegrasses use a large amount of water and prefer to he irrigated, but are able to survive through periods of drought by going into dormancy. Additional stresses such as a close height of cut or a higher traffic situation will warrant supplemental irrigation to prevent dormancy. While there are some varietal differences, Kentucky Bluegrasses in general are not considered highly drought tolerant.