Acer palmatum

El Acer palmatum It is one of the most important species of deciduous trees and shrubs in ornamental gardening. Originally from Asia, it is a set of plants that look great on patios, terraces, and of course in those paradises we call gardens.

There are different varieties and many cultivars, and it is likely that new ones will come out as the years go by. But, although some have green leaves, others red or others multicolored, the care they need is the same.

What is the origin and characteristics of the Acer palmatum?

El Acer palmatum, known as Japanese palmate maple, Japanese palmate maple, polymorph maple or Japanese maple, is a species native to Southeast Asia, specifically Japan and South Korea, and according to the Wikipedia some say also from China. It was described by Carl Peter Thunberg and published in Systemat Vegetabilium. fourteenth edition 1784 the year.

It is characterized by reaching heights between 5 and 16 meters, although there are some cultivars, such as Little Princess, that do not exceed 2-3 meters. Its trunk can be solitary or branch from near the ground, and its crown is usually pyramid-shaped when young, or rounded and wide when mature. The leaves are palmately lobed composed of 5-7-9 acute lobes and reach a size of 4 to 12cm in length and width.. These are of various colors, predominantly red, purple and green tones.

It blooms in spring, producing flowers with 5 red or purple sepals and 5 off-white petals. The fruit is a winged bi-samara about 2-3cm long that protects a 6-8mm seed.

Subspecies

Three are known:

• Acer palmatum subsp. palmatum: lives in the lower altitudes of central and southern Japan. It develops small leaves, 4 to 7cm wide, with 5 to 7 lobes that have double serrated margins. The wings of the seeds measure 10-15mm.
• Acer palmatum subsp. amoenum: They live in the highest altitudes of Japan and South Korea. The leaves are 6-10cm wide, 7-9 lobed, with serrated margins. The wings of the seeds measure 20-25mm.
• Acer palmatum subsp. matsumurae: lives in the highest altitudes of Japan. It is the one with the largest leaves, 9 to 12 cm wide, with 5-7-9 lobes whose margins are double serrated. The wings of the seeds measure 15-25mm.

Japanese maple cultivars

About a thousand cultivars are known to be propagated by grafting. Leaf color can be single (light green or yellow to dark green, red, or purple) or variegated.

Generally, do not exceed 5 meters in height, which makes them especially interesting for growing in small spaces, and even in pots. Some examples are:

• atropurpureum: Its leaves and branches are wine red, except in summer when they are greener.
• Aureum: develops light yellow leaves.
• Butterfly: the leaves are green with white margins.
• masumurasaki: develops purple leaves.
• Seyriu: has leaves whose lobes are like needles, very thin, green turning dark red in autumn. It is a cultivar that comes from the variety Acer palmatum var. dissection.
• tropenburg: the leaves are purple.

What uses does it have?

El Acer palmatum used only as an ornamental plant, either as an isolated specimen, in hedges, pots. In addition, in their places of origin they have been working for centuries as bonsai, especially the varieties with smaller leaves.

Its slow growth and easy maintenance -as long as the weather is right- have made the Japanese maple one of the most demanded plants by gardening enthusiasts.

What are the Japanese maple care?

So that this species can be well, that is, so that it can live at ease (and not survive) it is very important that the temperatures are mild all year round and that there are frosts in winter. It resists without problems up to -18ºC, but if we expose it to a temperature above 30ºC and leave it in the sun with a soil that is not too good, we will lose it.

Also, keep in mind that needs to be cold for a few months to hibernate, after which it will have recovered the necessary forces that will help it to resume its growth in spring. That is why in tropical and subtropical climates it is a difficult plant (rather impossible). Even in the coastal Mediterranean it is complicated (I speak from experience).

In areas with a Mediterranean or similar climate, I recommend planting it in a pot -with drainage holes- with akadama-type substrates with 30% kiryuzuna, or 5mm or smaller volcanic clay alone or mixed with 30% kanuma. But if you live in an area where summers are mild and winters are cold, you can plant it in containers - always with drainage holes - with substrates for acid-loving plants; and if the soil in your garden is acidic, that is, with a pH between 4 and 6, you can offer it a place to grow  .

Irrigation must be frequent, avoiding waterlogging. Use rainwater, bottled or lime-free. If the tap water has a pH greater than 6, dilute the juice of half a lemon in a liter of water, mix everything well with a spoon, and then check the pH again with pH strips or specific meters: if it is still high, add more lemon juice and check again.

During the spring and summer, it appreciates a regular supply of fertilizer., for example every 10-15 days. Use fertilizers for acidophilic plants following the instructions specified on the container once, and guano or other organic fertilizers the next. Just keep in mind that it is advisable to use liquid fertilizers if you have it in a pot, since if you use powdered or granular fertilizers, it will be difficult for the excess water to flow out through the drainage holes.

japanese maple multiplies by seeds in winter, which must be stratified in the refrigerator for three months at about 6ºC (or outdoors if the temperature is below 10ºC), and cultivars by grafting, which are usually grafted on the type species (Acer palmatum).

And finally, as for pests and diseases, there is nothing to worry about. It may have some cochineal if the environment is very dry, but nothing that cannot be removed by hand  . What is necessary to know is that it must be protected precisely from that, from the dry environment, as well as from direct sunlight. It will grow well if the environmental humidity is higher than 50% and if it is kept in semi-shade, but if not… its leaves will burn quickly.