Weed suppression by twelve ornamental ground cover species

Abstract

Twelve ornamental ground cover species were planted then monitored for 2 years to assess their relative usefulness for controlling weeds. Persicaria capitatum established quickly and covered the plots, but it was unsuitable for keeping weeds controlled because it died back each winter from frost damage. Acaena inermis and Muehlenbeckia axillaris also completely covered the plots within 12 months, and they effectively prevented weeds from establishing during a 5-month assessment period in the second year. Many of the other planted species also suppressed weeds well, and those that decreased the ratio of red to far red light intercepted by the soil underneath them best gave better weed control. Other ground covers that suppressed weeds well included Ajuga reptans, Coprosma acerosa, Grevillea lanigera, Juniperus procumbens, Pimelea prostrata, Sedum mexicanum and Veronica peduncularis. Some species, such as S. mexicanum and P. prostrata, shaded the soil less well at certain times each year.