Loblolly pine is the most commercially important timber tree in the southeastern United States and the second-most-common tree species in the country by count, after red maple. Native from east Texas to southern New Jersey, it grows in bottomlands, lowlands, and upland sites across the region. The name loblolly refers to a mudhole or mire, reflecting its tolerance of poorly drained soils.
In the landscape, loblolly pine grows fast—often 2–3 feet per year in youth—making it effective as a large-scale screen or windbreak. Needles occur in bundles of three, each 6–9 inches long, and shed after two seasons. Trees begin producing cones around age 10. Plant at wide spacing to allow full crown development; in dense plantings, thinning at intervals reduces disease pressure and improves individual growth rates. Acidic soils, moist to well-drained, suit it best, though it adapts to both sandy and clay sites.
Resin tapped from loblolly and related southern pines supplied the naval stores industry—turpentine, rosin, tar—that was central to the rural Southern economy for centuries. In managed forests and mature plantings, loblolly provides foraging and nesting habitat for red-cockaded woodpeckers and other cavity-dependent bird species.
Fusiform Rust
Spindle-shaped galls form on stems and branches of young pines, most commonly on trees under 10 years old. Galls enlarge over multiple seasons; orange, powdery spore masses erupt from the gall surface each spring. Branches die back beyond the gall; a stem gall can girdle and kill the entire tree.
No fungicide eliminates established galls. Cut out infected side branches cleanly below the gall and dispose of material off-site. Trees with main-stem galls cannot recover and should be removed. Avoid siting loblolly pine directly adjacent to oaks, which host the alternate spore stage of the fungus. Select rust-resistant seedling stock from nurseries or state reforestation programs when planting in high-pressure areas.
Pine Pitch Canker
Sunken, resin-soaked cankers on branches and main trunk; shoot tips die back and turn brown; heavy resin bleeding at infected sites; progressive dieback of scaffold branches.
Prune infected branches at least 6 inches below visible canker margins using sterilized tools; destroy all removed material. No curative fungicide is available. Maintain tree vigor through correct infrequent watering; avoid mechanical wounds to bark and surface roots.
Diplodia Tip Blight
New shoot tips wilt and collapse in spring while needles are still expanding, turning brown and remaining stunted. Small black fungal fruiting bodies (pycnidia) form at the base of infected needles and on cone scales. Resinous lesions may develop at the base of infected branches. Repeated infections cause progressive dieback from branch tips inward.
Apply a registered fungicide (thiophanate-methyl or copper-based) beginning at bud swell, before candles begin to elongate, and repeat at 10–14 day intervals through candle expansion. Prune and destroy all infected shoot tips. Avoid overhead irrigation. Rake and remove fallen needles and cones. Reduce tree stress through adequate soil moisture and avoiding mechanical injury, as the pathogen preferentially attacks weakened plants.
Lophodermium Needle Cast
Second-year needles turn yellow then brown, typically from the base outward, and drop prematurely in spring and early summer. Small black elongated fruiting bodies appear on shed needles. Heavy infection visibly thins the canopy.
Rake and destroy all fallen needles each autumn to cut overwintering spore load. Avoid overhead irrigation. Apply a copper-based or chlorothalonil fungicide beginning when new needles reach half their mature length in early summer, with a second application 3–4 weeks later. Maintain adequate spacing to promote air circulation.
Pine Needle Scale
White, elongated, oyster-shell-shaped scale encrustations along needle surfaces; heavy infestations cause needle yellowing, premature needle drop, and progressive canopy thinning.
Apply horticultural oil spray in early spring during the crawler stage. A second application in early summer controls late crawlers. Prune and dispose of heavily encrusted shoots.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.