Cones have short, stout, triangular spines. Loblolly pine is monoecious. Loblolly pine is a prolific and consistent seed producer in the Coastal Plain and produces large amounts of seed every 3 to 6 years in the Piedmont.
Germination is epigeal and is enhanced by bare mineral soil.
Loblolly pine is predominantly found on Ultisols but can grow on a wide variety of soils including Entisols, Spodosols, and Altisols. Loblolly pine is moderately tolerant of shade when young but becomes intolerant with age. It invades oldfields, clearcuts, and other disturbed sites. In the absence of fire, loblolly pine is replaced by climax hardwood forest. Flowering is initiated in the summer, and staminate and pistillate buds develop in the fall.