Date of this Version
Acorn weights ranged from 2 g to over 9.5 g, and their sizes ranged from 19.4-25.5 mm diameter. Roots first appeared from a hole in the bottom of a planting pot 17 days after planting and continued to 64 days after planting. Root germination by weight class of acorns was: those under 5.5 g 31%, 5.5 to 6.5 g 76%, and those over 6.5 g 100%. Shoots first emerged 27 days after planting, and the last emerged 65 days after planting. Production of emergent above-ground shoots for the same weight classes of acorns was: 23%, 64%, and 60%. Of 300 acorns planted into a tall, warm-season prairie sod an estimate of considerably fewer number of above-ground shoots was seen in the field than the 52% found in the greenhouse germination test. After four seasons of growth no seedlings of red oak could be found in the tall warm-season prairie area. Of the 24 seedlings from the germination test only 11 were barely surviving after five years of growth in a cool-season grass sod of mostly smooth brome.