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Botanical Name – Acer truncatum
Botanical Name – Acer truncatum
Common Name – Purpleblow Maple or Shantung Maple
Native to – Northern China
Botanical Information –First described by Alexander Bunge in 1833. A small tree to 30 feet often with twisted branches densely packed together. Leaves are 5 to 7 lobed. The leaves as they unfurl in the spring are a distinct red and quickly turn to a light green background with the leaf veins and edges showing a distinct purple tone. As the leaf matures and hardens the leaf color becomes a very nice bluish green. The Bark is very rough and fissured, almost cork like. Autumn color is a nice butter yellow but not consistently from year to year.
General – Acer truncatum is a tree not familiar to most simply because it is not widely available. From a bonsai perspective it has many good attributes and some that make it a little more difficult. However the good attributes far outweigh the difficulties as far as I’m concerned. The only problem with this tree is the length of the leaf petiole which is longer than one would like for the small and medium sized tree. This can be overcome by constant pruning back of the new growth:it is possible to make a good looking 10 inch bonsai. The outstanding feature in my mind is the character of the bark. It is highly fissured even on young trees and makes an outstanding display both during the summer and most of all the winter. The corky bark extends to the secondary branches leaving only the branch tips which are smooth. It is this character that will make for a bonsai that looks as though it’s an ancient tree. One would not go wrong in having this tree be part of their deciduous tree collection.
Cultivars – Akikaze nishiki (variegated leaves)
This tree likes more sun than the other maples. If given too much shading, it will become leggy and slender making the job of branch ramification all that much more difficult. Full sun in the morning until noon or shortly thereafter is required, and perhaps some in the late afternoon would not be a bad thing for the tree in a bonsai container. The leaves of this tree don’t seem to be bothered by direct sunlight as long as adequate moisture is provided.
When grown in the ground, this tree is hardy to Zone 5, which makes it one of the more hardy deciduous trees. Minimal winter protection for Zones 7 and above is all that is required. In zones 6 and lower, some root protection is recommended in the form of pine needles over the container or a simple cold frame.
During the growing season constant evenly applied moisture is needed. This tree does not seem to mind the effects of dissolved minerals and chlorine in tap water, but an occasional soil flushing would not be a bad thing.
Any good complete commercial fertilizer at the recommend strength and frequency during the growing season would be more than adequate. If your existing feeding program uses a diluted fertilizer approach, then a more frequent application is advised.
Summer pruning of this tree should be done on a regular basis to keep the growth in check and promote additional budding where ever possible. Heavy structural pruning or trunk chopping can be done on this tree during the mid summer as this tree does not bleed all that profusely and buds back quite readily. At this writing we have tested leaf pruning and it does a good job at helping leaf reduction, but the best approach is constant summer cutting back of the new growth. Let the new growth grow out to 2 or 3 internodes and then cut it back to the first node and continue this until the new growth matures later in the spring.
Wiring on young trees should only be done during the fall and winter. On older trees, wiring can be done during the mid to late summer without much risk of girdling.
Repotting young trees should be done every other year as long as they are growing vigorously. Older trees in good health should only need it every 2 or 3 years. As always though, the roots of the tree should be looked at every year during repotting season. Repotting should be timed to coincide with the onset of root growth in the early spring prior to bud break.
Propagation is typically through seeds. It should be noted here that seed is difficult to obtain. .If seed are available, seed with a green samara when collected will enhance germination. . Cuttings on this maple have not been successful.
Seed – Stratification for 90 days at 38 degrees prior to planting.
Pests and Diseases
The types and number of pests and diseases will greatly depend upon your location and the spraying program that you have established for your trees. During the years that I have grown this tree I’ve never had a problem with the typical bugs like mites and aphids, but if you get an infestation they can be controlled with commonly available insecticidal sprays using the recommended methods that come with the product. For those who don’t like to use insecticidal sprays these pests can be kept under reasonable control by using a strong spray of water late in the day just before dark. Aphids tend to locate themselves at the soft new growth. Mites tend to be on the underside of the leaves at the leaf veins. Scale can appear both during the summer and winter months and appear at branch junctions. They are sometimes difficult to notice.
This tree seems relatively resistant to the typical maple diseases of verticillium wilt and anthracnose.
|January 2005||August 2008||April 2009|