Quercus incana
Common Name(s):
Previously known as:
- Quercus cinerea
- Quercus oblongata
- Phonetic Spelling
- KWER-kus in-KAN-nuh
- This plant has low severity poison characteristics.
- See below
- Description
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Bluejack Oak is a thicket-forming deciduous large shrub or small tree with blue-green leaves found in the coastal and Piedmont of NC. Its native habitat is well-drained sandy soils of barrens, ridges, and shaded woods of the Atlantic and Gulf coastal plains of the United States, from Virginia around Florida to Texas and inland to Oklahoma and Arkansas
The trunk is short and the crooked branches form an open, irregular crown. The acorns are formed biennially and are loved by wildlife. The blue-green leaves are attractive but no fall color. It is often found growing in a shrub form to about 20 feet tall.
This is a drought-tolerant tree for well-drained soils in full sun to partial shade. The smaller size makes it a perfect shade tree for those with smaller yards but still can provide a haven for wildlife. It is a host plant for the larvae of the Imperial moth (Eacles imperialis), as well as numerous butterflies, including Banded hairstreak (Satyrium calanus), Edward's hairstreak (Satyrium edwardsii), Gray hairstreak (Strymon melinus), White-m hairstreak (Parrhasius malbum), Horace's duskywing (Erynnis horatius), and Juvenalis duskywing (Erynnis juvenalis).
Insects, Diseases, or Other Plant Problems: Numerous insect and disease pests, but the damage is rarely significant. Susceptible to oak wilt, anthracnose, cankers, leaf spots, powdery mildew, and oak leaf blister. Potential pests include scales, oak skeletonizers, leaf miners, aphids, galls, orangestriped oakworm, buck moth, whitemarked tussock moth, and lace bugs.
The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common pests and insects.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Quercus
- Species:
- incana
- Family:
- Fagaceae
- Life Cycle:
- Woody
- Country Or Region Of Origin:
- Southeastern U.S.A to TX
- Distribution:
- AL, AR, FL, GA, LA, MS, NC, OK, SC, TX, VA
- Wildlife Value:
- Oak trees support a wide variety of Lepidopteran. You may see Imperial Moth (Eacles imperialis) larvae which have one brood per season and appear from April-October in the south. Adult Imperial Moths do not feed. Banded Hairstreak (Satyrium calanus), which have one flight from June-August everywhere but Florida where they emerge April-May. Edward's Hairstreak (Satyrium edwardsii), has one flight from May-July in the south and June-July in the north. Gray Hairstreak (Strymon melinus), has three to four flights in the south from February-November and two flights in the north from May-September. White-M Hairstreak (Parrhasius m-album) has three broods in the north from February-October. Horace’s Duskywing (Erynnis horatius) has three broods in Texas and the deep south from January-November, and two broods in the north from April-September. Juvenal’s Duskywing (Erynnis juvenalis) has one brood from April-June, appearing as early as January in Florida. Acorns provide food for birds, squirrels, raccoons, and deer.
- Play Value:
- Wildlife Food Source
- Edibility:
- Acorns (nuts) are edible after tannins are leached or boiled out.
- Dimensions:
- Height: 30 ft. 0 in. - 55 ft. 0 in.
- Width: 25 ft. 0 in. - 45 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Native Plant
- Shrub
- Tree
- Woody Plant Leaf Characteristics:
- Deciduous
- Habit/Form:
- Irregular
- Open
- Spreading
- Growth Rate:
- Slow
- Maintenance:
- Low
- Texture:
- Medium
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Loam (Silt)
- Sand
- Soil pH:
- Acid (<6.0)
- Soil Drainage:
- Good Drainage
- Very Dry
- NC Region:
- Coastal
- Piedmont
- USDA Plant Hardiness Zone:
- 7a, 7b, 8a, 8b, 9a, 9b
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Fruit:
- Fruit Color:
- Brown/Copper
- Display/Harvest Time:
- Fall
- Fruit Type:
- Nut
- Fruit Length:
- < 1 inch
- Fruit Description:
- Biennial round acorns are 1/2 inch, brown with light stripes, red-brown scales on the cup that covers half the nut.
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Flowers:
- Flower Color:
- Gold/Yellow
- Green
- Flower Inflorescence:
- Catkin
- Insignificant
- Flower Bloom Time:
- Spring
- Flower Description:
- Male flowers are drooping yellowish-red catkins in spring. Female flowers are produced singly or in pairs on short stalks.
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Leaves:
- Woody Plant Leaf Characteristics:
- Deciduous
- Leaf Color:
- Blue
- Green
- Leaf Feel:
- Glossy
- Leathery
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Leaf Shape:
- Elliptical
- Ovate
- Leaf Margin:
- Entire
- Hairs Present:
- Yes
- Leaf Length:
- 1-3 inches
- Leaf Width:
- < 1 inch
- Leaf Description:
- Thick leathery, glossy, blue-green with short hairy petiole, base acute to rounded, apex acute with a bristle on the tip. Undersides veins are prominent blue-green and hairy. Leaves are tardily deciduous often remain on the tree late into the year. 2-4 inches long and 1/2 to 1 inch wide.
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Bark:
- Bark Color:
- Black
- Dark Gray
- Surface/Attachment:
- Furrowed
- Bark Plate Shape:
- Square
- Bark Description:
- Thick, dark gray to black furrowed with square plates
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Stem:
- Stem Color:
- Brown/Copper
- Red/Burgundy
- Stem Is Aromatic:
- No
- Stem Buds:
- Hairy
- Stem Bud Terminal:
- Cluster of terminal buds
- Stem Cross Section:
- Angular
- Stem Form:
- Straight
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- Red-brown buds, oval with hairy scales, brown twigs 5-angled hairy when young.
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Landscape:
- Landscape Location:
- Lawn
- Landscape Theme:
- Butterfly Garden
- Nighttime Garden
- Pollinator Garden
- Design Feature:
- Shade Tree
- Small Tree
- Attracts:
- Butterflies
- Moths
- Pollinators
- Small Mammals
- Songbirds
- Resistance To Challenges:
- Drought
- Problems:
- Problem for Horses
