Japanese maple: Diseases and Remedies (Explained for Everyone)

NOTE: In this article, Japanese maple and Acer palmatum may be used interchangeably; in fact, Acer palmatum is the botanical name for Japanese maple.

Japanese maples are part of traditional Japanese landscaping and garden design, and originated in East Asia. Japanese maple trees are used in a lot of different things. If you want to try Momiji tempura yourself, make sure to use young, freshly picked leaves early in the season because they can be bitter and make you sick. Classical Japanese art and poetry can be found in the tree.

Why does my Acer palmatum roots have rot?

Root rot on your Japanese maple (Acer palmatum) can be fatal if not treated with care. For this reason, we strongly recommend that you follow our guide to keep your plant alive if the symptoms occur: Root soft and blackened.
Japanese

Why does my Japanese maple have gray mold spots?

A particular fungus that frequently affects flowers and spreads quickly is known as gray mold spots. This fungus is most likely to blame if you see any brown (or gray) spots. Don’t ignore these signs because doing so could cause your plant to die.

Our Solution

The answer is obvious once you recognize the cause of the problem. Most frequently, it results from the Acer palmatum being overwatered. We strongly advise you to remove the damaged plant parts, cut off the diseased roots and leaves, and then repot your plant in a new container with sterile potting soil.

Why does my Japanese maple have leaf spots?

Leaf If your plants exhibit symptoms like rapid color changes in the leaves or leaves that wilt or droop, we give you all the information you need to recognize them and rescue your plants. For owners of Japanese maple, this kind of illness is among the most distressing.

Why are my Japanese maple leaves turning yellow?

In the world of horticulture, yellowing leaves are undoubtedly the most common problem. The two main causes of this problem are overwatering and a lack of nutrition.

When it’s overwatering, simply reduce your watering frequency, and if you think it’s a nutrient deficiency, here’s how to check it:

Each deficiency produces a different yellowing on the Acer palmatum in question, here’s how to spot them:

  • The first symptom of a magnesium deficiency is yellow patches between leaf veins on elder leaves. The leaf’s core turns yellow while the veins stay green. The edges of the leaf yellow last.
  • Another indicator of iron deficiency is yellowing between leaf veins, but young leaves on plant tops and branch tips are first affected.
  • Sulfur shortage first affects the youngest leaves, turning them entirely yellow.
  • Leaf edges turning bright yellow but inside leaf remaining green are signs of potassium insufficiency. The symptoms first appear on older leaves, and the leaf edges quickly become dark.
  • A broad yellowing indicates a nitrogen deficiency. Yellowing starts with older, inner leaves. Yellowing spreads as it advances, eventually touching new leaves as well.

Our Solution

According to the symptoms mentioned above, you just have to act accordingly. You can reduce your watering frequency, or fix a deficiency in Potassium, or Nitrogen, for that, you just have to buy a special soil for your deficiency, a consultant in a gardening store will know perfectly well how to inform you.

Is my Japanese maple sunburned?

It is simple to determine whether your Japanese maple (your Acer palmatum) has sunburn. Your plant will change color in this instance, beginning to turn yellow or white, much like it does on us.

Sunburned

As we saw above, if your Japanese maple receives too much water or not enough light, the leaves may also change color.

The bottom of the yellow leaves with a shaded area closer to the base can be examined to determine if they have been sunburned. If this part remains greener, the yellow leaf is most likely sunburned and not something else.

Why are my Japanese maple leaves turning brown?

The classic sign that a plant has been overexposed to direct sunlight and sunburned is the development of browning leaves. Rest assured that while this may probably save your plant from dying, it will adversely affect its growth.

Should I leave my Acer palmatum in direct sunlight?

No! Don’t leave your Acer palmatum (or Japanese maple) in the sun if it displays the symptoms mentioned above; that’s why it’s in such a bad situation.

Our Solution

As explained in the paragraph above, the solution is simple, just place your Japanese maple in a place where the light does not reach it directly, in this way and with a correct watering, your plant should resume its life rather quickly.

Why are my Acer palmatum leaves drooping or wilting ?

When you become dehydrated, this usually happens. Large plants are more vulnerable since they need more water on a regular basis than smaller plants.

Drooping

An easy way to know if your Acer palmatum is lacking water is to under-weigh its pot, if it looks light, it means that the soil and the roots are probably quite dry, and therefore need water!

Our Solution

If the soil in your plant’s pot is completely dry, you will need to start by moistening it so that the roots will also benefit from the water. A common mistake is to drown the Japanese maple right after a dry period thinking that it needs a lot of water.

This is the case, but giving too much water at once is the best way to finish it off, you should actually water the soil normally, resuming a quiet watering rhythm.

Caring Tips for Acer palmatum

Water Occasionally

Water is necessary for your plant to live, but timing and amount of watering must be balanced. Overwatering could have disastrous effects on your own name, as we already mentioned.

The best way to know if your plant needs water or not is to touch the soil, if you feel it is still wet, it is probably a good idea to wait a few more days.

Always keep temperatures stable

It is also a good idea to keep your Acer palmatum at a stable temperature (especially if it is kept indoors!). At GreenShack, we generally recommend staying in the 65 and 85 degrees F range. Of course, do not place your Acer palmatum near a source of hot (or cold) air such as A/C units, radiators or the like.

Keep your Japanese maple Dust-Free

This one is about houseplants. Your indoor plants’ leaves get dusty just like your furniture does. The problem is that this might prevent photosynthesis from beginning, which would result in the plants gradually losing their color.

For your Japanese maple, this would be a true descent into hell, and it would also appease the pests.

Take a microfiber cloth and gently massage the plant’s leaves to get rid of the dust. Use a damp cloth to make dust removal easier, but avoid using corrosive materials like rubbing alcohol!

Keep drainage in mind

If you have a tendency to overwater, you need to keep an eye on your drainage, we advise you to opt for a pot with drainage holes if it is not already the case and a saucer.

In the meantime, if you don’t have holes in your pots, you can add volcanic rocks (or any rocks with holes) at the bottom of your pot, this way it will create a channel so that the water doesn’t stay in your skin too much (to avoid that roots start to rot!)