Japanese maple: planting cultivation maintenance and pruning

There are many varieties of Japanese maples, of different sizes, but all without exception have more or less cut foliage, of great beauty, adorning themselves with autumn colors of the most beautiful effect, igniting the parks and gardens of their sublime tones. Depending on its height in adulthood, this tree can be planted singly, in groups, in rockeries and even, for the smallest varieties, in large tubs. You can’t resist its charm, whether it has variegated foliage, purple, gold or different greens. But be careful to offer it all the living conditions it needs to thrive and to choose the varieties best suited to the climate and the soil in its garden. Let’s do a check in.

Plant a Japanese maple

Japanese maple is a deciduous tree who particularly appreciates the situations slightly shaded and it must be installed sheltered from prevailing winds in cold regions even if it is quite hardy (this means that it resists frost quite satisfactorily). However, only young shoots are vulnerable in certain regions where spring frosts are still rife because they can really damage them.

Although it does not like either the scorching full sun or the scorching heat, it still needs a beautiful light because it is what allows it to keep the magnificent color of its foliage. Note, however, that the purple varieties are the ones that need full light the most.

As to solhe must be light, moderately acidic et costs (which retains humidity), but the Japanese maple hates having its feet in water. So the ground should be well drained. Be careful, this tree does not appreciate at all the calcareous soil to which it is even downright intolerant.

The different varieties of Japanese maples are marketed in a clod. They can therefore be planted almost throughout the year (except in winter). However, the best period to install a Japanese maple in the ground is thefall and the planting method is the following :

  • Dig a fairly generous planting hole which should be at least twice as large as the root ball.
  • Place at the bottom of the hole a drainage layer of about twenty centimeters (pebbles, pebbles, etc.),
  • Prepare a suitable mixture with 40% topsoil, 30% so-called heather soil and 30% very high quality planting soil or, better still, compost. We insist that Japanese maple should never be planted in calcareous soil. On the other hand, it can be satisfied with a neutral soil as long as it is not heavy.
  • Sift the planting soil and add two large handfuls of powdered horn.
  • Put a first layer of this earth on the draining bed.
  • Soak the root ball in water without taking it out of the pot until it is completely soaked.
  • Take the root ball out of the pot and gently untie the roots without hurting them.
  • Place the shrub in a root ball in the center of the hole.
  • Place a stake in order to direct the shrub during the first months if necessary and to maintain it in case of strong wind.
  • Carefully fill in the hole with suitable soil, taking care not to bury the collar, which must absolutely be flush with the natural surface of the ground.
  • Pack the soil well without mistreating the roots, and make a small watering basin.
  • Fill the bowl with a good layer of homemade compost or hemp mulch, dead leaves and/or bark.
  • Water copiously.

If one wishes plant several Japanese maplesit is necessary to space them from each other by 2.50 to 3.00 m for large varieties and 2.00 m for smaller ones.

The planting a Japanese maple in a container is identical to planting in the ground. We therefore do not forget the draining bed to be placed at the bottom of the pot before placing the sifted soil. Clay pebbles work just fine. Obviously, we choose a container with a pierced bottom, sufficiently deep and wide, at least 50 cm deep and in diameter. It is important to be vigilant in terms of watering because the soil dries very quickly in pots.

Caring for a Japanese maple

As with any shrub, this one needsregular watering during the first years following its planting, and more frequent in summer as long as it is still frail, as well as during the few weeks following its installation in the garden or in a pot, as this favors its rooting. Be careful, however, not to let its roots bathe and not to water on frosty days.

Check the condition of the liens which hold it to the stake and replace them with larger ones as the trunk thickens. After some time, it is quite possible to remove the tutor which becomes totally useless.

And mulching is strongly recommended because it slows down the evaporation of water. The soil thus remains very cool to meet the needs of the Japanese maple. Putting a mulch at the base is also very useful to protect the roots of the tree against severe frosts, knowing however that the different varieties easily withstand -10 to -14°C if they are not too exposed to the icy wind.

From March to November, care is taken to aerate the surface of the soil all around the foot of the tree thanks to hoeing allowing weeding at the same time. About the Japanese maple pruning, it is not absolutely necessary. In the spring, we are satisfied at most with eliminating the dead wood.

And shrub fertilizer should be done twice a year if planted in a jar, and it is useful to renew part of the earth because it is rapidly impoverished under such conditions. It can possibly be placed in the shelter under a porch if the winter looks particularly harsh. A winter sail can be wrapped around the tray after planting. But this last point is not mandatory because in most climates, the Japanese maple is able to spend all winters in pots without being protected down to -10°C. After a few years, the maple grown in a container must be repotted in a larger container.

Japanese maple pests and diseases

In poor growing conditions, this tree is sometimes the target of parasites and diseases, namely:

  • aphidswhich is eliminated with sprays of black soap diluted in lukewarm water.
  • mealybugs which must be dislodged by numerous sprays of a mixture composed of one liter of water, a teaspoon of 90° alcohol, black soap and vegetable oil.
  • Defoliating moths that can be removed either with wormwood infusions, or with decoctions of tansy or pyrethrum in regular sprays.
  • Leaf burns, favored by climatic conditions unsuited to Japanese maple. This is why it is essential to choose a place that is particularly well suited to this tree before planting in the ground. Leaf burns follow exposure to hot sun and strong dry winds or even salty winds in coastal regions. These are as many environmental stresses that harm this type of tree. A young plant can be moved just like a maple in a pot, but there is not much to do on a Japanese maple that has been planted for several years and whose leaves then fall prematurely.
  • black spot disease, which requires prompt treatment. You can use a manure of nettles, a decoction of horsetail or buy a copper fungicide.
  • Armillary or root rot, a serious fungal disease that attacks the root system and eventually kills the tree. We eliminate the affected parts that we burn and we remove the earth on a good fifty centimeters depth because the fungus in question spreads easily. The hole thus formed must be left as it is for a good year and planting in this place should be avoided thereafter for at least 4 years.
  • The verticilliosea cryptogamic disease due to the presence of the fungus Verticilla which little by little deprives the tree of sap until it dies by drying out. To avoid this disease, do not plant a Japanese maple in calcareous soil and, if it is grown in a pot, it is necessary to ensure that this container is well pierced. But whatever the conditions, its roots must not be immersed in water. Beware of excessive watering. The only solution to adopt in case of verticillium wilt is to cut the affected parts even if it means unbalancing the silhouette of the tree.

Apart from verticillium wilt, which is quite common in these specimens, the Japanese maple is a tree that does not pose a problem. We can also see that it does not require special care. It is not very sensitive to diseases and parasites when it benefits fromexcellent conditions and is planted in the right place. So don’t hesitate to indulge yourself by choosing various varieties to enhance your outdoor space.

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