|
| Name |
Ornamental
- Sorbus - Joseph Rock - Mountain Ash |
| Cultivation |
Sorbus
‘Joseph Rock’ requires well-drained soil and moisture in summer.
A neutral to slightly acidic, well-drained, loamy soil is best for this
plant. Full sun and good air circulation are also important. Sorbus ‘Joseph
Rock’ is a good lawn specimen because it can tolerate the lime applied
to the lawn. This tree can be short lived if it is planted in poor conditions.
Unless there are problems, it is best not to prune this naturally graceful
tree. If it has dead, damaged or crossing branches, remove them only in
the dead of winter on a dry day or in summer (late July to early August),
pruning as little as possible. The only disease problem of ‘Joseph
Rock’ is one that afflicts other rose family members: fireblight.
This occurs when warm spring weather occurs in conjunction with heavy rains.
The symptoms of this bacterial disease, which enters the plant through its
flowers, include tip dieback and blackening of twigs. If it shows symptoms
of fireblight, wait for a dry, sunny, spring day and cut out the affected
areas; disinfect your pruners between each cut. Do not prune it in wet weather!
Fireblight also affects other rose-family plants, such as Cotoneasters,
Pyracantha, and hawthorn, so you may already know if it is a problem in
your garden. If so, avoid Sorbus. |
| Family |
Rosaceae
Genus:
Common Name: |
| Genus |
Sorbus |
| Synonyms |
Sorbus
Joseph Rock, Joseph Rock Rowan, Mountain Ash, Rowan |
| Known
Hazards |
None
Known |
| Range |
A
fairly frequent early-20th century introduction from China. It is native
to places that have summer rain, so supplemental water in summer is important.
|
| Height |
20ft
x 8ft (6m x 2.4m) in 20 years, ultimate height 25ft (7.6m). |
| Habitat |
A
deciduous and fully hardy tree that can tolerate a wide range of soils and
conditions. |
| Characteristics |
An
outstanding tree. One of the finest yellow fruiting autumn trees. Erect
compact tree bearing bunches of cream-white flowers in spring. Compound
leaves with many leaflets turn beautiful shades of red, orange and yellow
in autumn and form a perfect back-cloth to the clusters of globular fruits.
These turn creamy-white to deep amber-yellow and remain on the tree well
into winter. The alternate pinnate leaves have leaflets which are much smaller
and more pointed than those of Common Rowan. Buds are small and reddish. |
| Edible
Uses |
None
Known |
| Medicinal
Uses |
None
Known |
| Other
Uses |
Some
forms of Rowan are widely planted as street trees while others are grown
as ornamental trees in parks and gardens. |
| Propagation |
Stratify
seed surface sown in early spring, or sow seed when ripe in fall, into
a somewhat sheltered spot, fertile and well-draining soil. Even moisture
appreciated. Full sun to light shade; often suitable in more exposed locations,
and can tolerate exhaust fumes. |
| Cultivars |
Cultivars
may be whip-grafted in winter or early spring, or grow from softwood cuttings
in summer, to remain true to type. |
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