Pin oak.

At a glance

Care level

Easy

Plant type

Deciduous tree

Light

Full sun

Indoor light

Direct sun

Water

Every 7 to 14 days

Mature size

70 feet

Growth rate

Fast

Hardiness

USDA 4 to 8

Bloom time

Mid to late spring

Care

Plant this tree in an open space where it has plenty of room to spread its wide canopy. Keep an eye out for yellowing leaves, which can indicate iron chlorosis in high pH soils. Make sure it gets consistent moisture while it is getting established in your yard.

Watering

Water deeply during dry spells to keep the root zone moist.

Feeding

Apply a balanced fertilizer in early spring if growth seems sluggish.

Pruning

Remove dead or crossing branches during the dormant winter season.

Repotting

This tree is meant for outdoor planting and should not be kept in containers long term.

Soil

Moist, acidic, well drained

Soil pH

Acidic

Temperature

-35 to 35°C

Humidity

40 to 70%

Safety

People

The foliage and acorns contain tannins that can cause digestive upset if ingested in large quantities.

Children

The acorns are a choking hazard for small children and should be kept out of reach.

Contact allergens

The leaves and bark are generally safe, but some individuals may experience mild skin irritation from contact with the rough bark.

Airborne allergens

The wind-borne pollen is a significant allergen for many people during the spring flowering season.

Edibility

Acorns contain tannins that must be leached thoroughly before they are safe for human consumption.

How to identify it

• Deeply lobed leaves with bristle tips
• Pyramidal shape when young
• Lower branches often droop downward
• Small round acorns with shallow caps
• Smooth gray bark on young trees

Height

15 to 22m

Spread

10 to 15m

Leaves

green, deciduous

Flowers

yellowish, green, 1 to 2cm

Fruit

brown, Autumn

Problems to watch for

• Oak wilt · A fungal disease that blocks the tree's water-conducting vessels.
• Chlorosis · Yellowing of leaves caused by iron deficiency in high pH soils.

Growing it

Propagation

seed

When to plant

Spring, Autumn

Plant these trees in areas with consistent moisture to avoid the stress that leads to disease.

Grows well with

• Red maple · They share similar moisture requirements and thrive in the same woodland settings.
• River birch · This tree also enjoys the moist, rich soils that the pin oak prefers.

Similar species

• Scarlet oak · It has a similar leaf shape but prefers drier, upland sites.
• Northern red oak · It is a close relative with a similar growth habit but larger acorns.

Science

Family

Fagaceae

Genus

Quercus

Order

Fagales

Class

Magnoliopsida

Native range

Eastern and central United States.

Conservation

This species is common and not of conservation concern.

It thrives in floodplains and low-lying areas where it can tolerate periodic standing water.

Value to wildlife

larval host plant, acorn food source

Pollinators

bees, beetles

Uses

shade tree, ornamental specimen, wildlife habitat

Taxonomy resolved against GBIF.

Questions people ask

Why are my pin oak leaves turning yellow?

It is likely suffering from iron chlorosis due to alkaline soil.

How fast does a pin oak grow?

It is a fast grower, often adding 60 to 90 centimeters per year.

Where the name comes from

The name palustris means of the swamp, referring to its preference for moist habitats, while pin oak refers to its short, twiggy branchlets.

Good to know

• Pin oaks are often used in landscaping because of their symmetrical, pyramidal shape.
• They are very tolerant of wet, poorly drained soils compared to other oak species.
• The lower branches often droop toward the ground as the tree matures.
• They grow relatively fast for an oak tree.