The fan-shaped maple (Acer palmatum) is without doubt the most popular ornamental maple for the garden. The specialist garden trade offers numerous varieties with different leaf and growth forms, from the bonsai-like dwarf to the stately solitary shrub. The botanical species name refers to the Latin word “palma” for palm and is probably a reference to the hand-shaped lobed leaves.
The natural home of the fan maple is East Asia. Wild specimens can be found in the Korean and Japanese mountain and lowland forests on humus-rich, permeable soils. The European garden career of the fan maple began at the end of the 18th century, when the Swedish doctor and botanist Carl Peter Thunberg became aware of the small tree during a trip to Japan and brought it with him to Europe. At this time the fan-shaped maple had been in gardening culture in Japan for centuries and there were already several breeding forms. In addition, the fan maple was already one of the most popular trees for bonsai art at that time.
The wild species of the fan-shaped maple usually grows in several stems and forms an expansive, loosely branched umbrella-like crown. Its branches and twigs are remarkably thin and contribute a lot to its elegant filigree appearance. The fan-shaped maple grows relatively slowly: it increases in height and width by about 20 to 30 centimeters per year, can grow to a height of five to seven meters in our case and can grow to about the same width when standing freely. The bark has a grey-olive hue and the bark a fine, longitudinal cracked pattern.
The opposite, deciduous leaves of the fan maple are already very variable in the wild species: the leaves are usually five to seven-lobed, more rarely nine-lobed, and between six and ten centimeters long and wide. The lobes start already below the middle of the leaf, become evenly narrower and are tapered at the end. The foliage sprouts fresh green and turns golden yellow to carmine red in autumn. The different cultivated forms show leaf forms and colours that differ strongly from those of the wild species.
The flat-rooted maple grows in sunny to semi-shade locations and opens its flower buds in May. The small hermaphroditic single flowers stand in purple grapes in the leaf axils and form a pretty contrast to the fresh green shoots.
Like almost all species, the fan-shaped maple forms the typical winged fruits. Botanically speaking, these are little nuts that have grown together in pairs. The wings are at a relatively obtuse angle to each other. At first the fruits are strikingly wine-red in colour, in late summer they turn brown when the seeds ripen.
Although the fan-shaped maple can also cope with semi-shade layers, its most beautiful crown shape and autumn colouring is formed when it is standing in full sunlight. The location should be protected from the wind and have a favourable microclimate, as the young shoots of the fan maple are somewhat sensitive to late frost.
A loose and permeable, sandy, humus loamy soil is ideal for the fan-shaped maple. Pure sandy soils should be improved with plenty of humus and then give the fan maple a slightly shady location, because the leaves dry out very quickly in full sunlight and lack of water. Very heavy, wet or compacted soils are the death sentence for a fan maple. Sooner or later, most specimens here will be attacked by the incurable Verticillium wilt. As far as the pH value is concerned, the ornamental wood is relatively adaptable. Although it prefers weakly acid soils with little lime, it also grows in neutral to slightly alkaline soil.
As young fan-shaped maples are somewhat sensitive to frost, they should preferably be planted in spring after the late frosts have subsided. If the soil is loamy or clayey, it must be loosened to a depth of 30 to 50 centimeters over an area of about four square metres. The best way to do this is to dig deep into the Soil with two spade leaves, the so-called rigolen. In the process, plenty of building sand is worked into every layer of soil. In unfavourable soil conditions, experts also recommend planting in flat raised beds or on earth mounds about 30 to 40 centimeters high in order to avoid problems with waterlogging. It is very important not to place the pot ball too deep into the Soil when planting: a fan maple is better tolerated if the pot ball looks out of the Soil one to two centimeters further than if it is two centimeters too deep into the plant hole. Ideally, the surface of the pot ball should not be covered with soil after planting and should be at about the same level as the surrounding soil. Thorough watering after planting is important, and you should also sprinkle a few handfuls of horn shavings under the bush and then mulch the root area with bark humus. If you want to cultivate your fan-shaped maple in a tub, it should have a volume of at least 20 litres. It is best to use normal, permeable potted plant soil and repot the ornamental shrub into a larger container every three to five years, depending on the rate of growth.
The filigree leaves of the fan maple quickly show dry damage due to lack of water. On sandy soils in a sunny position you should therefore not wait too long before watering, otherwise the tips of the leaves will dry out. However, do not water over the foliage, but with a watering rod directly in the root area. A regular nutrient supply of the plants is not absolutely necessary, but can accelerate the growth especially in the first years after planting considerably. Simply sprinkle horn chips or a mixture of horn chips and mature compost in the root area of the plants every spring or autumn. Fan-shaped maples cultivated in tubs must be watered and fertilized regularly – preferably with a commercially available liquid green plant fertilizer. Stop fertilizing by mid-August at the latest and do not pour as abundantly from September, otherwise the new wood will not ripen and your fan maple will not show a nice autumn colour. For the wintering of the pot-trees, it is completely sufficient if you move these simply densely at a house-wall where they are protected against precipitation, winter-sun and cold east-winds to some extent. The roots of the fan-shaped maples are extremely frost hardy, so it is not necessary to insulate the bucket against the cold.
Fan-shaped maples usually form a beautiful, even crown by nature and do not age. Cutting measures are therefore rarely necessary. If you need to correct the shape of your fan maple, you should do so in August. Maples generally do not tolerate cutting in winter and spring very well, as most species tend to bleed and the cuts are susceptible to fungi. Always remove disturbing shoots right at the base and avoid cutting back into the older wood. The plants sprout only quite sluggishly and the crowns often appear disfigured for a long time if older branches are simply shortened. Cuts that interfere with the basic structure of the crown should be made immediately on the still very young plants.
The fan-shaped maple and its cultivated forms should always be planted individually because of their extraordinarily picturesque growth form and beautiful autumn colours. If you want to plant several specimens, you should choose different varieties and plan enough distance between the trees so that they can develop their typical growth forms. In combination with other small autumn colours such as the feather bush (Fothergilla) and the pseudo hazel (Corylopsis), late flowering perennials such as the monkshood and the saxifrage (Saxifraga cortusifolia), autumn crocus and various ornamental grasses you can create beautiful plant images. The woody plants also look good as easy-care tub plants for roof gardens, balconies and inner courtyards. In addition, they are very distinctive Rhododrendron companions, as they stand out well with their autumn colours against their dark green foliage.
Bloodgood’: up to four metres high and wide variety with black-red foliage and scarlet autumn colouring
Green slit maple ‘Dissectum’: up to three metres high and four metres wide variety with hemispherical, often soil-covering crown shape; very filigree, finely divided leaves with golden yellow autumn colour; slow growing; also available as red leaf variety ‘Dissectum Atropupureum’ on the market
Golden Treasure’: upright growing, three metre high and two metre wide variety with yellow foliage and bright yellow autumn colouring.
Orange Dream’: broad upright growth; three metres high and wide: beautiful orange-red shoots, yellow-green summer and orange-yellow autumn colouring
Oridono Nishiki’: spherical habit; two metres tall and wide; white-coloured, slightly pink overflowing leaves; yellow-orange autumn colouring
Rainbow’: broad growth habit; three metres high and wide; leaves on older shoots dark red, on young shoots light red; carmine red autumn colouring
Shaina’: only one metre high dwarf form with spherical crown and red foliage; very beautifully formed leaves with wine-red colour and light red autumn colour; well suited for tub culture
The wild form of the fan-shaped maple can be reproduced relatively easily by sowing. Collect the ripe seeds and keep them cool and dry throughout the winter. Before sowing in March, they should be stratified for about a week in a box of moist sand in the refrigerator. The germination rate is relatively low at 20 percent. After emergence, the young seedlings must be protected from late frost damage with fleece. In the first year they should be wintered frost-free in the cold house and only in the second year they should be further cultivated in the open in the bed. The propagation of the different varieties of the fan maple is a case for professionals: almost without exception, the cultivated forms are propagated by grafting, namely in late summer by so-called “lateral pointing” or “lateral plating” of the well-wooded scions on potted seedling rootstocks of the wild species Acer palmatum. Further cultivation of the freshly grafted plants and wintering must take place in the greenhouse. Only in the second year are the seedlings potted in larger containers and then usually further cultivated in foil tunnels in the nursery until they have reached their sales size. With some more vigorously growing varieties, such as the red-leaved ‘Atropurpureum’, propagation by cuttings is also possible in greenhouses with the appropriate cultivation equipment. For the hobby gardener, however, the method is also not practicable.
Diseases and pests
The fan-shaped maple rarely suffers from pests. A great threat, however, is the incurable Verticillium wilt already mentioned above. In the event of an infestation, individual shoots dry out first because the fungus blocks the pathways. Within a few years the whole plant often dies. Powdery mildew also occurs more frequently, but causes fewer problems for the plants. In sunny locations with dry soils, dried leaf tips or major leaf damage due to sunburn often occur in summer. The warm winter sun also occasionally causes frost cracks in younger plants, which can easily be prevented by shading or whitewashing the trunks and main branches.
Fan maple in the our store-Shop
I am Don Burke, one of the authors at My Garden Guide. I am a horticulturist that cultivates, grows, and cares for plants, ranging from shrubs and fruits to flowers. I do it in my own garden and in my nursery. I show you how to take care of your garden and how to perform garden landscaping in an easy way, step by step.I am originally from Sydney and I wrote in local magazines. Later on, I have decided, more than two decades ago, to create my own blog. My area of specialization is related to orchid care, succulent care, and the study of the substrate and the soil. Therefore, you will see many articles dedicated to these disciplines. I also provide advice about how to improve the landscape design of your garden.