Technical Abstract: Cultivated timothy (Phleum pratense L.) is an important grass for hay production in temperate North America. It is underutilized in management-intensive rotational grazing systems because of its poor persistence when frequently defoliated. The objective of this study was to compare families selected for forage yield under frequent defoliation, families derived from old turf sods, and cultivars for agronomic performance under frequent and infrequent harvest managements (4 vs. 2 harvests per year). Forage timothy was generally superior to turf timothy for most traits. Forage selections averaged 9.4 and 4.9% higher forage yield compared to cultivars under infrequent and frequent harvest managements, respectively, indicating that selection for higher forage yield under frequent harvest improved forage yield under both harvest frequencies. There were differences among the four types of turf (golf course fairways and roughs, cemeteries, and lawn/roadways), but these differences were not closely related to mowing height or frequency, perhaps due to the small sample size. Some turf collections ranked high for net herbage accumulation under frequent harvesting, but most turf collections were also characterized by a high frequency of regrowth panicles under either or both harvest frequencies. Timothy germplasm from old turf sods may have value in developing new timothy cultivars with improved tolerance to frequent defoliation and efforts should continue to gather and evaluate collections from a range of turf types and locations.