Japanese maple or. Acer palmatum atropurpureum is a smaller tree or larger shrub, which is very decorative because of the shape of its leaves and therefore a popular ornamental tree. It has been grown in Japan for more than 300 years. It grows very slowly up to 27 feet, has a domed canopy, and because of that very suitable for growing in containers. The twigs and petioles of this tree are smooth, the leaves are 5 to 9 rags and have a serrated edge. They grow from 1.57 to 4.72 inches in length. In the spring they are different colors from green, yellow to reddish. Red tones become more pronounced in the fall. The flowers are grouped into short inflorescences that develop into winged fruits. Japanese maple requires moderately moist, slightly acidic, fertile and well-drained soil for its growth, and grows best when not exposed to strong wind or direct sunlight.

Japanese maple: Germination and cultivation

Level of difficulty: 4.

Plant seeds are the product of sexual reproduction, which means that the offspring are not identical to their parents. In the case of Acer palmatum, this means, that some offspring will have green and some reddish leaves. This fact is in our favor as we acquire different colors of bonsais.

Under the right conditions, the germination of dry maple seeds is usually less than 50%. Germination is counteracted by hormonal processes that temporarily inhibit the possibility of germination, as well as the seeds, have a real hard shell that protects the sprout from external influences. If we want the seed to germinate, we need to wait for a while for all the hormonal processes in the seed to complete, and at the same time, we need to do some procedures that will soften the shell so that water and oxygen can enter the seed. This process is called cold stratification, which simulates the winter environment. In the wild, germination can take many years, so you should be patient and take time for these seeds.

To reduce the risk of various diseases, remove the wings from the seeds.

Place the seeds into a germination pot and pour with warm water (104 - 122 F). Close with a lid and leave in a warm place for 24 hours. Initially, most seeds will probably float on the water, but in 24 hours, almost all will sink.

The next day, repeat the whole process: pour off the water and again pour the seeds with warm water (104 - 122 F), then cover with a lid and leave in a warm place for 24 hours.

After two days of soaking in warm water, remove the seeds with a spoon from the germination pot and place them gently on the germination paper. Two tablets of sowing substrate put one by one on the lid of the germination pot and fill with lukewarm water. Let them soak well (about 15 minutes). Then remove them from the water with a spoon and place in the pot. With a spoon spread them gently to get a slightly moist substrate. Then put the seeds into a pot and mix them well into the substrate. Close the pot with the lid, and place it into the refrigerator for 4 weeks. The ideal temperature for cold stratification is 39.2 F. Germination pot should never touch the back wall of the refrigerator, as it is usually much colder and could, therefore, when touching, freeze the substrate. Even though this would not damage the seeds, it would greatly prolong the stratification process.

After 70 days, take the pot out of the refrigerator and place it in a warm and bright place. Within 14 days some seeds should sprout already. If you notice a germ, remove it from the germination pot and place it in a biodegradable sowing pot, into which you spread the remaining two tablet sowing substrates.

11 weeks after the beginning of germination
11 weeks after the beginning of germination
3 months after beginning of germination.
3 months after beginning of germination.

During the first growing season, make sure your little bonsai is most of the time in the shadow, as the direct sun is likely to damage young leaves.

You can plant the remaining sprouted seeds in your garden if you live in a favorable climate. If you are going to grow the plants as a container, make sure that the roots do not freeze during the severe winter. But never plant them in nature or forests. 

Finally, here are some ideas that may inspire you to design your bonsai.