Looking back 40 years, Jeff Stone said the greenhouse and nursery industry was barely a blip on the radar of Oregon agriculture. Now nursery stock is consistently among the state’s most valuable farm commodities, with sales of $947 million in 2017. Stone, executive director of the Oregon Association of Nurseries, said the momentum really took off in the 1980s and 1990s. Based in Wilsonville, about 15 miles south of Portland, the association represents 800 members, including 600 growers. It is a success story driven by the availability of water, along with the Mediterranean climate — cool, wet winters followed by hot, dry summers — and rich soils of the Willamette River Basin.