Bonsai are living things that require our attention everyday. They have certain requirements to live a long life. Remember that bonsai is an art form that can last a lifetime (or many) under the correct care. Unfortunately, there can be a little confusion when it comes to bonsai care. That is why I have created an easy to follow bonsai learning guide comprised of all the key areas of bonsai care. Reading this guide is a MUST.
This guide aims to troubleshoot what may be causing the problem with your bonsai tree. People will insist they have followed all of the instructions but they will often miss a key care principle when looking after their bonsai tree. After diagnosing your sick bonsai, you may be able to save it, or it may be too late.
Even if your bonsai tree has died, all is not lost. Now you have a new pot for your collection, and hopefully some knowledge of what you did wrong so you can change how you approach bonsai tree care next time. My first bonsai tree given to me in 2007 died due to neglect, although the next tree I bought is still with me to this day!
Is My Bonsai Dead?
There are many normal reason for a tree’s colour to change, including seasonal changes. But if the foliage on your tree begins to change for no apparent reason, it could be cause for concern.
On conifers, like Junipers, you may see the lush green color of the leaves start to become pale and dull. If this trend continues, it will eventually turn a yellowish brown color. Discolouration on conifers often happens when the tree isn’t receiving the required amount of light (e.g. when it’s living indoors). It can also happen if the tree doesn’t receive enough water and begins to dry out.
For other trees, like maples, discolouration in the foliage could be caused by continued exposure to the afternoon sun. This is known as leaf burn. Alternatively, like the conifers, under watering a deciduous tree will caused the leaves to dry up and eventually fall off completely.
Checking For Life
If your tree is discoloured or brittle, the next step is to check to see if the tree is still alive. Luckily, there is a simple way to test this, and you won’t need any special tools to do so.
Look at your tree. The bark of your tree protects the life underneath it. To see if your tree (or a particular branch) is still alive, all we have to do is remove a small portion of the top brown bark to see if the next layer of the tree is green. Green is the color of life.
Scrape off a small portion of the bark with your fingernail. If you don’t find green under the surface, keep scratching. When you get down to hardwood and don’t uncover green, your tree has died (or, at least that portion of it).
When checking a brach, start with the tip first. If it’s dead, then move back toward the trunk and try again. Sometimes branches die from the tip back, and if the end of the branch has died, you can cut back to the portion that still shows green.
The vast majority of bonsai species need to be grown outside. Not under a veranda, or deck that shades the sun in any way. For some reason, due to misinformation, newcomers to bonsai believe that bonsai are an exception from normal trees and therefore they believe that their bonsai can live inside. That is not the case. Just like an ordinary tree, your bonsai needs sun, air and natural climate cycles. Don't think you can fool nature because you think there is enough sun inside your room :) If your bonsai tree is an Azalea, Ficus or other tree species that can tolerate living indoors, there are some guidelines to follow around placement. Place the bonsai in a cool room. Place it near but not right up against a window where it will receive a few hours (2-4) of morning or late afternoon sun. This picture of an azalea bonsai below was sent in from a customer. The heat pump in the background is the culprit. Never place your bonsai in a room with a fireplace or heat pump. The temperature fluctuations are a too great. The customer also admitted to under-watering the bonsai, which is easy to do when the bonsai is placed in such a hot environment.
Displaying the bonsai inside for too long
It is great to enjoy your bonsai tree inside from time to time. It is important that you don't do this too frequently though as it will affect the health of your bonsai. Place the bonsai in a relatively well lit area of your home which is near but not in front of a window. For up to 3 days (absolute maximum) you can display your bonsai here. Be sure to check the soil for moisture and you can even mist the foliage. After 3 days, place the bonsai back outside for at least another month or two before being brought back inside. Bonsai are trees after all, and so they enjoy being kept outside for the majority of the time (unless they're an indoor species such as Ficus). Trees that appear weak or sick should not be displayed inside.
Bringing the bonsai inside because it's stormy outside or the tree looks sick
Rather than bringing your bonsai indoors during extreme conditions, place your tree in a sheltered outdoor position like a patio with enough sun. If your bonsai starts to decline in health, do not bring it inside! Instead, follow our revival guide below.
Watering too little or not well enough
We generally sell our bonsai in 6 and 8 inch pots. That doesn't leave much room for soil. Bonsai are amazing little trees that can survive in these small containers, although that beauty has it's price. Watering! Water every morning unless it has been raining all night. A sprinkle of water won't do either. Make sure to water on a low setting (rose watering head works best). Water once, wait 30 seconds, water again. The aim here is to saturate the entire rootball. No dry spots!
Constantly moving the bonsai
Your bonsai tree keeps track of where the sun rises and sets each day. When your bonsai is constantly moved it confuses the bonsai's rhythm and is forced to work out where the sun is so it can grow in that direction. If trees were meant to move, they'd all have legs! Keep it in one spot for a while :)
Constantly 'fiddling' with the bonsai
Resist the urge to constantly trim your bonsai tree during the growing season. A stem that is growing outward during spring and summer is trying to produce more leaves that will allow the tree to photosynthesis more and therefore grow stronger. A general rule of thumb is to allow growth to extend 8 leaves then cut the stem back to 4 or 5 leaves. If your bonsai doesn't have leaves (conifer such as a juniper) then aim to cut back only to the original branch from which it extends. Cut back growth every few weeks during the growing season.
Giving the bonsai too much or too little sunlight
For full sun loving trees, aim to provide 5-8 hours of direct sunlight each day. For other trees that don't enjoy part shade, they can get by with 5 or so hours of sunlight each day. Other trees like maples enjoy protection from the heat of the mid day sun. They prefer morning and late afternoon sun.
A single yellow branch or small group of leaves/needles in one part of the tree
Some trees grow so dense that the light cannot penetrate into the centre of the tree. This causes foliage in these areas to go yellow and die off. This does not mean your bonsai is dying. Look at the growing tips. Are they green and lush? If so, your bonsai is healthy.
Sometimes, due to shipping or mis handling, a branch may bend, and weeks later it turns yellow and or looks dry and shrivelled. This generally only happens with small branches that can sometimes snap easily. Unless it is a primary branch or the trunk, there is no cause for concern as another branch should take its place in time.
Lastly, a yellow single branch could indicate overwatering. Overwatering your bonsai causes the roots of the bonsai tree to rot from being constantly soaked in water. In this case, reduce your watering and or repot in better bonsai soil (a mix of half coarse pumice and half tui outdoor container mix). Sieve out fine particles under 2mm if possible.
Soil washing away from the surface exposing the roots
This can happen naturally over time or sooner if you water aggressively which washes the stones from the surface of your bonsai. Simply apply more fine pumice, propagation sand or moss if you prefer. The first two can be found at Bunnings.
Reviving Your Bonsai Tree
For all of the problems listed above, I have given solutions. Although there are some extra things that you can do to save your bonsai tree. First of all though, if your bonsai looks like the below picture. There may be some hope.
If your bonsai looks like this, it is dead and is not worth saving. It would be best to learn from your mistake and try again.
If it doesn't look as bad as the tree above then the best thing to do first of all is to move the bonsai into a place that receives only 2 or 3 hours of very early morning sun each day (for about 10 days), slow introducing it back into full sun each day. When a bonsai is stressed, (unless the cause is lack of sunlight) its ability to utilise the sun's rays is reduced. When a bonsai is under stress, its ability to uptake water is also impacted, so we must also reduce our watering. Mist every morning and night. Water very well when the soil starts to dry. Once you begin to see new growth and the bonsai is able to tolerate more and more sun. You should be back on track. Some branches may not have made it through. These can be cut back to the nearest primary brunch or the bark can be stripped back to create a 'deadwood' effect called 'jhin'.
Other issues such as diseases, fungal, and pests should be approached in their own unique way. You can find the cause of the issue by Googling your tree species and the symptoms present. For example; 'Juniperus procumbens white patches' or 'Chinese elm black bugs'. Sometimes the cause is unknown even to us and a quick search online will present detailed results with images to compare. We receive many emails a day from growers all over New Zealand. We wish we can answer everyones queries but it may take us some time to respond if you require our help.