There's No Reason To Call 9-1-1 When Your Bonsai Needs First Aid!

Posted by Jason on 21st Jun 2015

When properly cared for, a bonsai tree can be a wonderful addition to your home and family. A single tree can live for a century or more, while ever so slowly expressing its own personality through its growth and changes over the years.

Unfortunately, like others in your household, a bonsai can fall prey to a number of common ailments. The good news is that these trees are relatively hearty, and most common diseases can be taken care of. As with all living things, the key is to be attentive, and to give aid to your bonsai as soon as you notice any warning signs.

Here's what to watch for.

Common Bonsai Tree Maladies And Their Solutions

1 - Yellowed / Falling Leaves

The most typical symptom a bonsai tree will display is a rapid yellowing in some or all of its foliage, with previously-healthy leaves dropping off quickly. This can be due to a number of issues:

  • Underwatering. This is the most common cause of yellowing leaves, and also the easiest to fix. If the soil around the roots ever feels completely dry, it's being under-watered.
  • Stress. Honestly - your bonsai tree can feel stress too! Occasionally foliage loss accompanies a sudden change, such as moving to a new location with a notably different climate.
  • Frost damage. Bonsai trees prefer warm weather and can be quickly hurt or killed by low temperatures. One should never be kept someplace where freezing are possible.
  • Weed killers. Move your tree away from any spraying to keep them safe. It's rare -but possible- for strong weed killers to also kill bonsai trees.
  • Chlorosis. This is a mineral deficiency, and the solution is to give your bonsai some vitamins. Any gardening supply shop will sell soil treatment products to add the magnesium, manganese, and iron your bonsai needs. Try this if you can't find another cause, and your bonsai will likely perk right back up.

2 - Infestation

Your bonsai, like all plants, is susceptible to a large number of invasive species which consider it a delicious treat. It's important to keep a close eye on your bonsai from day-to-day, as most infestations will first show themselves through damage or alteration to the leaves.

Here are some common symptoms:

  • Ants. Ants by themselves aren't harmful to a bonsai, but seeing many of them on a bonsai indicates there may be aphids, which definitely are harmful. Luckily, aphids are visible to the eye. Most of the time, an infestation can be removed simply by gently washing the bonsai with soapy water.
  • White foam. This is commonly called "cuckoo spit," and is a form of cocoon for developing insects. Immediately wipe or wash it off, to prevent an outbreak.
  • Irregular notching on the edges or center of leaves indicate vine weevils, which are deadly to bonsai because their larva will hide in the soil and eat the roots. Currently, the only ways to deal with them are to very carefully repot the bonsai while removing the grubs by hand, or by soaking the soil in (expensive) proprietary chemicals.
  • Fine webbing on leaves is usually a sign of red spider-mites, which are tiny and too small to remove by hand. Contact insecticides are unfortunately the only option here.
  • Mildew. This can form on leaves or stems if the bonsai is kept in a consistently damp, poorly-ventilated room. If possible, avoid ever doing this, as the only solution to mildew is immediate removal of all affected area(s).

With proper care and treatment, your bonsai can lead a long and happy life. Keep an eye on this blog for more care tips!