Foliage

• Leaves are narrow, lanceolate, and willow-like, typically 2–5 inches long and ½–1 inch wide.
• Glossy green in summer, turning shades of yellow, golden brown, or russet in fall.
• Deciduous, but leaves often persist into winter before dropping.
• Young leaves emerge with a slight reddish tint in spring.

Flowers

• Monoecious (producing separate male and female flowers on the same tree).
• Male flowers appear as elongated yellow-green catkins (hanging clusters).
• Female flowers are small, inconspicuous, reddish-green, and found near leaf axils.
• Blooms in mid to late spring (March–May), depending on climate.
• Wind-pollinated and not showy.

Fruit (Acorns)

• Produces small, rounded acorns that measure ¼–½ inch in diameter.
• Acorns have a thin, shallow cap covering about ¼ of the nut.
• Matures in two growing seasons, ripening in fall (September–November).
• Acorns are an important food source for wildlife, including birds, squirrels, deer, and small mammals.

Sunlight Requirements

Willow oak thrives in full sun (at least 6 hours of direct sunlight per day). It can tolerate some light shade but grows best with ample sun exposure.

Soil Preferences

• Adaptable to a wide range of soils, including sandy, loamy, and clay soils.
• Prefers moist, well-draining soil, though it can tolerate periods of drought once established.
• pH range: Slightly acidic to neutral (5.5–7.0).

Watering Needs

• Young trees require regular watering until well established.
• Once mature, drought-tolerant, though occasional deep watering during prolonged dry spells can improve vigor.
• Avoid waterlogged conditions.

Temperature & Hardiness

• Hardy in USDA Zones 5–9.
• Tolerates a wide range of climates, from humid southeastern summers to colder northern winters.

Fertilization

• Not necessary for established trees in nutrient-rich soils.
• If growth is slow or leaves appear pale, apply a balanced slow-release fertilizer (10-10-10) in early spring.

Pruning

• Minimal pruning required; mainly for shaping and removing dead or crossing branches.
• Prune in late winter to early spring before new growth starts.

Growth Rate & Mature Size

• Fast-growing, adding 2–3 feet per year under optimal conditions.
• Can reach 40–75 feet in height with a 30–50 foot spread at maturity.

Pest & Disease Resistance

• Generally resistant to pests and diseases.
• May occasionally encounter oak wilt, leaf spot, or gall-forming insects, though these are rarely serious threats.
• Keeping trees healthy with proper watering and mulching reduces stress-related issues.

Mulching

• Apply a 2–3 inch layer of mulch around the base, keeping it several inches away from the trunk to prevent rot and pests.
• Helps retain moisture and suppress weeds.

Wildlife & Landscape Uses

• Excellent shade tree for urban and residential landscapes.
• Acorns provide a valuable food source for wildlife, including deer, squirrels, and birds.
• Tolerant of pollution and compacted soils, making it a great choice for city planting.