The use of velvet bentgrass (Agrostis canina L.) on putting greens is limited by sparse knowledge on optimal maintenance. The objectives of this study were to determine the effects of rootzone composition (SS, straight sand, or GM, sand amended with 20% v/v garden compost) and irrigation regime (LF, light and frequent, or DI, deep and infrequent) on thatch formation, root development and playability. A study was conducted from August 2007 to October 2009 on a USGA green seeded in June 2007 with velvet bentgrass ‘Legendary’ at a coastal location in Norway (Landvik, 58° N). Compared with light and frequent irrigation, deep and infrequent irrigation improved root development in the 10- to 20-cm soil layer in the second year after sowing. A decrease in turf visual quality on SS receiving light and frequent irrigation in the second year was associated with low infiltration rate. Neither thickness nor content of organic matter in the mat layer were significantly affected by the treatments. A 20% higher surface hardness on SS vs. GM persisted only during the first year of the study.