Bartzella. Anderson. 1986. American Peony Society Award of Landscape Merit. American Peony Society Gold Medal winner-2006. APS ‘Best In Show’-2002. Full formed yellow flowers on large plants. Easily grown and is an excellent landscape plant for foliage after bloom. Bartzella has now been around for awhile and many new yellow intersectionals have made their way to the market. Still, Bartzella is clearly the best yellow peony. Week 6 bloom time. Seldom produces seed. (white lactiflora x Reath woody hybrid). Ships in late September to mid October.