Black spruce flowers in late May or early June in the southern portion
of its range and 1 to 2 weeks later in the northern portion. Female
conelets develop rapidly and contain mature seeds by about 3 months
after pollination (late August or early September). The cones release
seeds gradually over a period of years .
Beginning and ending of height growth is generally as follows :
Area Height growth begins Height growth ends
Lake States June 8-20 August 1-10
Maine late May-early June mid to late August
Alberta June 1 August 2
- 27. Fowells, H. A., compiler. 1965. Silvics of forest trees of the United States. Agric. Handb. 271. Washington, DC: U.S. Department of Agriculture, Forest Service. 762 p. 
- 65. Viereck, Leslie A.; Johnston, William F. 1990. Picea mariana (Mill.) B.S.P. black spruce. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 227-237. 
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