Page 197 - Tài liệu cây cảnh Bonsai4me Bonsai Basics

calluses; if necessary, the size of the scar can be reduced by carrying out major

pruning work in late Summer and Autumn.
Wiring In midsummer though indoor trees can be wired mid-winter
particularly if out of leaf. Care should be taken as bark marks easily. Healthy
trees can also be defoliated during Winter (if necessary) and mid Summer to
enable easier wiring.
Propagation Sow seed outdoors in Autumn or Spring. Greenwood cuttings
in Summer. Hardwood cuttings in Winter. Airlayering after spring growth has
hardened.
Pests and diseases Elm bonsai are not affected by Dutch Elm Disease as the
beetle requires the volume of wood only available to it in fully grown mature
trees. An attack (if it were to happen) would easily be dealt with by systemic
insecticides and fungicides on a potted tree in comparison to the problems
associated with eradicating Dutch Elm Disease on a fully-grown tree in the
ground.
Watch for aphids, leafhoppers and gall mites
Styles Suitable for all forms and sizes-especially good for the broom form

which replicates the natural shape of Ulmus.

Zelkova/ Elm Bonsai

Genus of about 6 species of deciduous, semi-evergreen trees occurring in
woodland, thickets and hedgerows in Italy, Greece, Turkey,Iran and Asia.
Zelkova have alternate, ovate to elliptic toothed leaves. Most species display
good fall colour of yellows and orange-browns.
Ulmus species and in particular Ulmus parvifolia/Chinese Elm are very often

confused with Zelkova species in particular Zelkova serrata/Japanese Elm.
Zelkova are classed as a seperate genus to Ulmus as they have fruits that are
unwinged as opposed to the winged friuts of Ulmus. Zelkova also differ in that
they have single-toothed leaves whereas Ulmus have double-toothed leaves.
(Ulmus are listed separately under their own species guide).
The usual Zelkova species used for bonsai is the Japanese Grey-bark Elm
/Zelkova serrata, however there is no reason why any of the smaller leaved
Zelkova species cannot be used.
Notes for bonsai cultivation
Zelkova parvifolia/Japanese Elms are often sold as indoor bonsai and as such
are acclimatised to indoor growing conditions, Japanese Elms sold as outdoor
bonsai and all other species of Zelkova should be cultivated outdoors. Japanese
Elms grown indoors (or in climates with very mild winters) will remain