For only the third time since the Perennial Plant Association's Plant of the Year program was instituted an ornamental grass, Panicum virgata 'Northwind'  has been given this designation. 'Northwind', is a 5 foot tall blue green switchgrass that turns golden in the fall. The fine flower panicles rise another foot or so above the foliage. 'Northwind' has a very erect and upright growth which makes it ideal for narrow sites. It needs sun, but is tolerant of most soils.…