Life History Reproduction and Early Growth Flowering and Fruiting Scarlet oak is monoecious. It flowers in April or May, depending on latitude, elevation, and weather. Seed Production and Dissemination Minimum seed-bearing age is 20 years, but maximum production does not occur until after 50 years of age. On the average, good seed crops occur every 3 to 5 years, although actual seed production may be irregular and unpredictable from year to year. More than 80 percent of mature scarlet oak acorns may be destroyed by insects.
Most insect damage occurs after acorn fall.
The proportion of uninfested acorns is usually highest in years of greatest seed production. Germination is hypogeal. As a result of recurrent shoot dieback, root systems of scarlet oaks may be many years older than shoots. However, individual flush lengths get progressively shorter as the season progresses. As the sprouts grow older, the rot spreads and may weaken the trees to a point where they break off during high winds.