Acer TRUNCATUM 'MONO'

Acer TRUNCATUM 'MONO' - Shantung maple 'Mono', Truncate maple 'Mono', Acer truncatum 'Mono'.

Can be grown in the bonsai style!

Maple is a genus of deciduous trees and shrubs in the family Sapindaceae, comprising more than 120 species and numerous ornamental forms. Native ranges encompass Europe, Asia, and North America, with the greatest species diversity occurring in eastern Asia. Maples are found in mixed forests, on mountain slopes, in river valleys, and in parkland landscapes. The second genus of the family - Dipteronia - is distributed only in China.

The plants have a rounded or broad, dense crown and large palmately lobed leaves with radiating venation. In autumn, the leaf blades take on brilliant shades of yellow, orange, purple, or reddish-brown, making maples some of the most ornamental trees of temperate climates. Shoots are usually light-colored, displaying various bark shades on young growth.

The flowers are small, yellow-green, gathered in loose inflorescences and appearing in early spring - simultaneously with the leaves or slightly earlier. The fruit is a double samara consisting of two winged seeds that separate upon maturity and are dispersed by the wind. The root system is predominantly shallow, which facilitates rooting but makes the plant sensitive to soil compaction.

Maple propagates by seeds and suckers. Most species are light-demanding, tolerate urban climates well, and are notable for their longevity: average life expectancy is 150-200 years, and individual specimens can reach ages of 300-500 years. Due to their ornamental appeal and hardiness, the genus is widely used in landscape gardening worldwide.

Shantung maple is a tree up to 10 m (33 ft) in height, with a broad, oval, open crown. The leaves are deeply 5-lobed, glossy, bright green, lighter beneath. The flowers are greenish-yellow, in corymbs. It blooms in late April to early May simultaneously with leaf unfurling; fruits ripen in October.

Maple seeds are samaras about 1-1.5 cm (0.4-0.6 in) long that ripen in different seasons. Most species, even under optimal conditions, have a natural germination rate of 20-50%. Merely remaining in the soil, they may germinate only after years.

Scarification substantially improves germination and seed swelling; without disrupting the outer coat, germination will be minimal. The outer coat is carefully filed or scratched with a hard tool without damaging the seed, after which seeds are soaked for 12-24 hours in warm water with the addition of stimulants (SUPERthrive, HB-101, Aminozol, Epin, or Zircon). Subsequent presowing preparation is conventionally divided into 3 scenarios depending on the species.

1. Acer BUERGERIANUM, Acer GINNALA, Acer ELEGANTULUM, Acer MACROPHYLLUM, Acer PALMATUM, Acer PLATANOIDES, Acer SACCHARUM, Acer TATARICUM, Acer TRUNCATUM (and most species absent from the list)

for successful germination require cold stratification. The seeds are placed in a small plastic zip-lock bag, into which slightly moistened peat moss or vermiculite has previously been added, from which water should not be expressed when pressed. Air is removed by moving a palm from the bottom to the zipper, the bag is sealed tightly and placed in the refrigerator on the bottom shelf. Stratification is carried out for 2-4 months at a temperature of 3-5 °C (37-41 °F). Once every 1-2 weeks, the contents are checked. If condensation appears, excess moisture is removed by gentle pressing, after which the bag is turned over. In case the substrate dries out, 1-2 drops of water are added. Once germination begins, the seeds are removed from the refrigerator and planted into prepared soil.

2. Acer CAMPESTRE, Acer GLABRUM, Acer GRISEUM, Acer JAPONICUM, Acer PSEUDOSIEBOLDIANUM, Acer SHIRASAWANUM (and challenging rare/montane/Asian species)

due to germination difficulty have an additional warm stratification stage. After scarification and soaking, the seeds are kept in a warm room at a temperature of 20-30 °C (68-86 °F) for 2-4 months. Then the seeds are placed in a plastic bag and undergo cold stratification (as described in point 1), sometimes with a repeated cycle. One should not be surprised by low germination rates; realistic expectations are only about 20-30%. Once germination begins, the seeds are planted into prepared soil.

3. Acer RUBRUM, Acer SACCHARINUM (and hybrids like Acer × FREEMANII)

do not require stratification and are sown immediately after scarification and soaking.

After any of the preparatory stages, seeds are sown into a light, air-permeable substrate to a depth equal to the seed size or with 0.5-1 cm (0.2-0.4 in) covering, moistened from a spray bottle, placed in a mini-greenhouse or covered with film, and germinated in the light, but not in direct sun, at a temperature of 18-22 °C (64-72 °F). Seedlings require ventilation. Overwatering and drying out of the sowings must be avoided.

Seedlings appear in 2-4 weeks; the maximum germination period may exceed 6-8 weeks, and some seeds may germinate only in the 2nd-3rd year. After the opening of the first true leaves, pricking out into individual pots is carried out. Cultivar forms are also propagated by grafting onto hardy rootstocks to preserve ornamental coloration.

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Maple prefers sunny or semi-shaded locations where ornamental leaf coloration is displayed most vividly. The plant is well-suited to urban conditions, resistant to wind and smoke. In the first years after planting, regular soil watering and mulching of the root zone are recommended to conserve moisture. The best results are achieved in fertile, loose, moderately moist soils with good drainage.

Watering is carried out regularly during hot and dry periods, approximately 10-15 L (2.6-4.0 gal) per plant, with a double dose after planting. In ordinary years, watering is performed once a month, and during hot spells - once a week. Maple can endure brief soil dryness, but full-fledged growth is achieved with steady moisture. The plant has a shallow root system, so loosening is performed carefully and shallowly. After planting, the root zone is mulched with a layer of 3-5 cm (1.2-2.0 in).

In early spring, sanitary and formative pruning is performed: damaged, crowding, and diseased shoots are removed. In variegated forms and brightly colored cultivars, green reverting shoots may appear, which are cut out to the base so they do not suppress the ornamental part of the crown. Fertilizers are applied annually: in spring - balanced fertilizers with moderate nitrogen content, and in summer - phosphorus-potassium mixtures that promote shoot strengthening.

Most maples are winter-hardy and do not require sheltering. Young plants in harsh winters are recommended to be protected by heaping the root collar area with fallen leaves or spruce boughs. If annual shoots freeze, spring pruning is performed - the crown recovers successfully through new growth. With age, the plant's winter hardiness increases.