Low Maintenance Ground Covers for Pacific Northwest Municipalities.

Ornamental landscapes can require considerable amounts of management related inputs, including irrigation, mowing or pruning, fertilization, and pest management. Reducing these inputs can have considerable benefits, particularly for municipalities that have limited budgets devoted to landscape maintenance. The objective of this study was to identify ground covers that can compete with weeds and maintain aesthetic qualities with minimal maintenance. In May 2015 we initiated a field experiment in Corvallis, OR to evaluate the performance of several putative low-maintenance ground cover species under two levels of mowing. The Experimental design was a randomized complete split-block with ground covers (10 species), and mowing (mowed or control) as factors. Selection of study plant species was informed using input from a municipal landscape manager stakeholder group and included three turfgrasses, Agrostis capillaris  L. ‘Puritan’,  Festuca rubra  L. ssp. commutata ‘Chantilly’, and Festuca rubra  L. ssp. rubra ‘Longfellow 3’, and 7 herbaceous and woody perennials:  Sedum spurium  M. Bieb ‘Tri-color’, Euonymus fortunei (Turcz.) Hand.-Maz. ‘Kewensis’, Juniperus horizontalis Moench ‘Blue Chip’, Herniaria glabra  L., Vinca minor  L. ‘Bowles’, Cotoneaster dammeri  C.K.Schneid, and Ceanothus gloriosus  J.T.Howell ‘Point Reyes’. Mowing occurred monthly at 10 cm; plant material was bagged and removed.  Plots were not irrigated or fertilized after establishment, and are weeded once annually.  Response variables included percent cover (0-100%) of desired plant, weeds, and bare soil.  A. capillaris, as well as F. rubra Chantilly and Longfellow 3 had the highest percent of plant cover (83%, 76% and 74%, respectively), followed by S. spurium which provided 52% cover. Mowing did not affect percent plant or weed ground cover. Our preliminary results suggest that turf is the most cost effective, low maintenance tolerable ground cover for municipal landscapes.