Eastern redcedar is a dioecious species,  and trees probably reach sexual maturity at about 10 years. Staminate  strobili or conelets begin to develop on male trees at the tips of  axillary branches of new scale-leaves. Pollen grains are formed by late  September in conelets having 10 to 12 entire-margined sporophylls.  Staminate strobili turn a conspicuous yellowish brown when they reach  maturity during winter, and thus male trees are readily distinguished from  ovulate ones.

    Small green conelets begin to develop by early fall or late summer on  ovulate trees but grow very little during the winter. They are borne  terminally on axillary branches of the new scale-leaves but do not become  conspicuous until late February to early spring. At this time the  microsporangial walls of the staminate conelets split longitudinally,  discharging the mature pollen. Pollen grains lodge at the end of the  micropyle of the many ovules in the conelet. Pollination is complete in a  few days when the conelet closes.

    Growth of the pollen tube is slow at first but becomes active by late  May or mid-June. Fertilization occurs in June and the mature embryo is  full grown in about 2 months, anytime from late July to mid-November,  depending on location. As the ovulate cone develops, greenish fruit-scales  form the outer fleshy protective coat of the berrylike cone. Cones change  color from green to greenish white to whitish blue and finally to bluish  as the season progresses.

    Each cone or fruit contains one to four (occasionally more) rounded or  angled brownish seeds, 2 to 4 mm (0.08 to 0.16 in) long, often with  longitudinal pits. The seed coat has a thick and bony outer layer and a  thin, membranous inner layer (23,47).