Fertilizing your Japanese maple bonsai tree can be immensely helpful. The tree grows faster and becomes much more sturdy quickly. However, it must be done in the right way and at the right time. Or else the tree will suffer. If you do not know how to properly fertilize your Japanese maple bonsai, it is best to avoid fertilizing the tree completely. The tree will continue to be healthy. This is an easy to care for plant. Continue reading Japanese maple bonsai care.
What is the best fertilizer for Japanese maple bonsai?
The best fertilizer for Japanese maple bonsai is a balanced, slow-release granular fertilizer. However, avoid fertilizers that contain high levels of nitrogen. Avoid any fertilizer with a “N” value greater than 15 in the NPK ratio.
Nitrogen spikes in the soil will produce elongated shoots and longer twiggier growth. On the other hand, lower nitrogen levels will lead to balanced and consistent over all growth. Instead of applying a lot of fertilizer for rapid growth, you should practice the right pruning methods to achieve a lot of growth on your Japanese maple bonsai.
Any fertilizer with a NPK value such as 15-10-8 or 10-10-10 should be effective for the Japanese maple bonsai tree. Do not worry about the values of P (Phosphorus) and K (Potassium) too much.
Furthermore, there are many proprietary Japanese maple bonsai fertilizers with a very low NPK content. For example 4-6-5 or 4-5-3 etc. Although these fertilizers are not harmful for your Japanese maple trees, these low levels do not really contribute much to the tree’s healthy growth. Hence, avoid investing in such fertilizers.
Finally, some people have a misconception that organic fertilizers such as cow manure, chicken manure, or horse manure should be fine. However, that is not the case. They can have a very high nitrogen content. Hence avoid such organic fertilizers.
When should I fertilize my Japanese maple bonsai tree?
The time of fertilizing your tree depends on the tree’s state. If the tree is in a dormant state or about to enter one, you should not fertilize it. Fertilize the tree while it is actively growing.
The best time to fertilize your Japanese maple bonsai tree is early spring, when the tree is already beginning to leaf out.
Japanese maples generally have two flushes of growth. First in the spring and again in the summer. Hence, fertilizing only in these two seasons is recommended.
All fertilization should stop before the fall season ends. If you fertilize the tree until fall, then the plant will have a hard time turning dormant in winter. Furthermore, if the tree is fertilized in fall, the tree will still be very active and have high chlorophyll levels in the leaves. This will have a negative impact on your bonsai’s fall color. Therefore all the fertilization should stop as November arrives.
In winter, there should be no fertilization as the tree should be dormant.
Having said that, fertilization time also depends on the region where you grow the bonsai tree. Some warmer regions (for example southern states) will have a longer growing season and a shorter dormant season. Here you can fertilize the tree for a more extended period of time. On the other hand, in colder states with distinct seasons and a relatively longer dormant season, the fertilization window will be smaller.
How to fertilize Japanese maple bonsai tree
Often the bonsai material you buy from the nursery already has fertilizer. Hence, for the first year you won’t need to feed the tree. Ask your nursery dealer whether the saplings have been fertilized already. This information will help you determine your fertilization schedule. In any case, I would recommend waiting for the season to be finished and then fertilizing from the new year onward. Continue reading about how to take care of Japanese maple bonsai seedling.
One very crucial information some bonsai growers (mostly new) forget is that a fertilized bonsai tree needs more water than an unfertilized bonsai tree. The tree will need more water to absorb all the additional nutrients from the fertilizer. If not watered properly after fertilization, the tree can suffer from leaf scorching or root burn. Continue reading about watering Japanese maple bonsai tree.
To fertilize your Japanese maple bonsai, you can use granulated (pellets) fertilizers or liquid fertilizers.
Whichever fertilizer you use, make sure all fertilization stops before mid-fall (October). Do not push new growth after that. Otherwise, the tree will not be able to go dormant at the right time in winter.
Read the manufacturer’s label on the fertilizer bag and apply less fertilizer than recommended. Do not push the plant too much or it will be unhealthy.
Liquid fertilizer for Japanese maple bonsai
Liquid fertilizers are easy to apply and fast acting, however, they do not last long. If you use liquid fertilizer, apply it 1-2 times a month. I would recommend applying it every 3 weeks. Typically, liquid fertilizer applications should stop after summer (after August). This will help the tree prepare to shutdown in the winter.
Remember, in Japanese maples, more fertilizers in the fall season also decreases fall color of the foliage. This is particularly detrimental for variegated Japanese maple varieties. More nitrogen in the fall will increase the green part of the leaf and hence less variegation.
On rare occasions, liquid fertilizer can also be used for maples that need a little bit of energy late in the season. Nevertheless, do not apply liquid fertilizer after mid-fall i.e. stop after October. Or else the tree will not shut down in the winter.
Because it stays in the soil for a brief period of time with a relatively low nitrogen content, it shouldn’t cause many residual buildup problems. However, it can certainly contribute to nitrogen buildup if used regularly. Therefore, spacing its application is advisable.
Granulated fertilizer for Japanese maple bonsai
On the other hand, granulated fertilizers are slow acting. They release nutrients over time as you water your bonsai tree. Read the manufacturer’s label to find out the fertilizer release time. For example, some fertilizers have a release time of 180 days, 90 days, 60 days or even immediate release.
While selecting granulated fertilizer, choose one without rounded pellets. This will prevent them from rolling off the container. Choosing a pellet fertilizer without a smell is also a good idea.
You can directly apply the pellets to the soil surface, however they will be hard to clean if decomposed. Instead, you can use fertilizer baskets or small tea bags to contain fertilizer pellets. This enables you to remove pellets when not needed.
Start applying granular fertilizer in spring as the tree buds start opening. Read the instructions on the fertilizer bag and know the release time of the fertilizer (for example, 180 days, 120 day and so on). This will help you determine the frequency of fertilizer application. Fertilization will be less frequent if the release time is longer.
As mentioned earlier, use baskets or tea bags to contain the pellets so you can remove the fertilizer in time. For example, some fertilizers have a 6 month release time. Which means that the tree is still being pushed late in the season, resulting in cold damage to the tree.
Don’t use slow releasing granulated fertilizer late in the season. Or else the tree will still be active in the dormant season and be more prone to freeze damage.
Overfertilizing Japanese maple bonsai
You can overfertilize some varieties of Japanese maple and get a six-foot tall tree in a single growing season. The problem is the tree quality will be poor.
You may be able to minimize the negative effects of overfertilizing Japanese maples in warmer climates. However, in colder climates, fertilizing your tree too much will harm it.
Overfertilizing will produce shoots with longer internodes.
It will also elongate the cells (streched out cells). The cells will have thin cell walls. This will make the tree less resilient to the winter season. Also, the tree will be prone to fungal infections or pseudomonas.
Hence it is always advised to use less than the recommended fertilizer dose.
