Quercus robur 'Irtha'
common oak 'Irtha'
A very unusual form of small deciduous tree, slowly reaching approximately 10m. The leaves are much reduced and a bit twisted, giving a kind of ribbony appearance. They form clusters at the branch ends which, with the fresh yellow-green leaves in spring, look a bit like blossom. The real flowers are inconspicuous but become acorns which show clearly amongst the leaves.
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Size
Ultimate height
8–12 metresTime to ultimate height
10–20 yearsUltimate spread
4–8 metresGrowing conditions
Moisture
Moist but well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Yellow Green | |||
|---|---|---|---|---|
| Summer | Green | |||
| Autumn | Brown Yellow | Brown | ||
| Winter |
Position
- Full sun
Aspect
East–facing or North–facing or South–facing or West–facing
Exposure
Sheltered Hardiness
H6Botanical details
- Family
- Fagaceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Spreading branched
- Potentially harmful
- Pets (dogs): Harmful if eaten - for further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
- Genus
Quercus can be deciduous or evergreen trees or shrubs, with entire, lobed or toothed leaves; flowers inconspicuous, followed by characteristic acorns; sometimes good autumn colour
- Name status
Accepted
How to grow
Cultivation
Suited to small-medium gardens. Grows in any well-drained but moisture-retentive soil in good light. For more information see tree cultivation.
Propagation
Propagate by hardwood cuttings in autunm
Suggested planting locations and garden types
- Architectural
Pruning
Pests
May be susceptible to oak processionary moth, aphids, caterpillars, leaf-mining moths and oak gall wasps
Diseases
May be susceptible to powdery mildews and honey fungus
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