Caring for Bonsai plants can be easy! Prevent your tree from becoming sick!

Caring for Bonsai plants is easy.

Whether you are new to this wonderful pastime, or a seasoned veteran, a little advice on what to avoid will never go astray!

It is neccessary to know about seasonal care too!

In caring for Bonsai plants YOU MUST OBSERVE THE FOLLOWING:

• Regular watering. Drought will leave a root system vulnerable to weakness and pests and disease. Grit will help to keep the soil cooler, and loam based compost will help with moisture retention. DO NOT OVERUSE RETENTION ADDITIVES!. Try and use up to 10% retention additives if necessary. Overuse will lead to soil compaction (fine soils without grit etc).

• Use good sterile soil when mixing composts.

• Prevent soil waterlogging and compaction, particularly in Winter. Caring for Bonsai plants, while easy, requires some thought during this season!

• Ensure balanced pH levels and soil health, and correct if ill health and pH imbalance is apparent. This includes testing the water that you give the Bonsai is pH neutral. A little either side will be ok, but generally too acidic or alkaline will hurt your Bonsai.

• Avoid large variations in temperature, particularly if there is a risk of cold damage or heat stress. Watch for cool changes.

• Avoid windy conditions, direct sunlight in large amounts (days on end in the full sun with minimal watering), still, damp air and excessive shade.

• Use organic feeds with low nitrogen levels.

• A little humus in the soil mixture will naturally deter pests and disease.

• Avoid watering the leaves of mildew-prone species.

• Remove decaying leaf litter, branches and debris to avoid bacterial growth and fungal infection.

• Ensure good soil drainage.

• Clean and protect wounds on the tree’s branches and trunk. Fungal infections start in wounds and can be passed onto other trees much like a flu among humans. Seal all wounds, particularly if the Bonsai is close to other trees. Caring for Bonsai plants can sometimes be like nursing a human!

• Choose a tree that will thrive in the climate where you live. Be mindful of sensitivity to the elements, pollution, disease, wind etc.

All living things contend with pests and disease, and Bonsai is no exception.

Bonsai trees can be subject to such damage, however, proper caring for bonsai plants will reduce the risk of infection .

In caring for Bonsai plants, success lies in your ability to identify symptoms of pests and disease, and to use the right cure. Are you ready to play doctor? 

The signs of poor plant health are easy to spot, and it will usually be the colour and quality of the foliage that will be the first tell tale sign of an infection. Dropping of needles and leaves, discolouration of foliage or your plant becoming limp are signs that something is wrong. 

ants on leaf


Red Spider Mites

Usually found in warm conditions, and more prominent with indoor varieties. The red spider mite is microscopic and barely visible with a microscope.

They live in colonies on the undersides of leaves, and often make fine white cobwebs in the joints between branches.

Your local garden store should stock an insecticide such as Malathion to assist you with eradicating the mites. 


Or greenfly/blackfly, are commonly found on deciduous trees, in particular, the maple.

They prefer the new soft shoots and leaves as their place of residence.

An insecticide containing bifenthrin would be more suited to the eradication of this pest, as Malathion may blacken young leaves. 

Root Aphids

White in appearance and appearing on roots. If infection has occurred, soak the roots in insecticide or apply spray. 

Woolly Aphids

Covered in a white woolly wax, this pest executes most damage on the bark of deciduous trees.

Best destroyed by squashing them with a cloth, or alternatively you can use a systemic insecticide. Unfortunately their woolly covering shields them from ordinary insecticides. 


Mainly found on pines, larch and spruce, these pests are sap – sucking insects and are very destructive.

To ensure your caring for Bonsai plants is not in vain, year round attention to this pest is necessary through the use of insecticides. 

Vine Weevil

Usually found in Europe and most commonly found on maples, camellias, azaleas, rhododendrons, pines, and junipers.

The beetle lays its eggs in the soil, and the larvae generate the most damage as they eat away the plants roots. How devastating!

Check your local garden store for chemicals such as permethrin, which can control larvae.

Important to note - this must be used at the critical time in late summer when the eggs hatch.

White Fly

Common in warm humid conditions. These sap – sucking insects attack mainly indoor varieties, and can be easily spotted as they fly around when disturbed.

The signature sign that your bonsai is infected, is the yellow spots on leaves. Ordinary insecticide should do the trick, or alternatively you can use a sticky insect tape.



Root Rot

Is a fungal disease, mainly associated with conifers such as Juniper and pine.

Root Rot is a serious disease, and once a plant is infected, there is very little that can be done.

To avoid root rot, water trees sparingly and allow for good soil drainage. 

Rust and Black Spot

Commonly associated with crab apple, hawthorn, cotoneaster, Prunus and Sorbus.

The tree's leaves will appear yellow and drop prematurely during mid-summer.

A visit to your local garden store should fix your problem, in combination with the elimination of all dropped leaves to prevent the disease from spreading.  

Coral Spot

Bright orange spots that form on the branches and trunks of Japanese maples and some elms. Coral Spot spreads easily through cross contamination, usually through gardening tools.

Coral spot is easily managed by removing affected areas of your Bonsai, and disinfecting gardening tools. 


A fungal disease that affects seedlings and is commonly mistaken for root-rot.

Seedlings will die suddenly for no apparent reason.

The best method for prevention is a Bordeux mixture, avoid over watering, maintain good ventilation, soil drainage, and good hygiene. 


Affects Rosaceae Family such as the crab apple & hawthorn. Symptoms include the blackening of stems and leaves.

This bacteria is airborne and is very difficult to manage and eradicate. Immediately after identifying these symptoms, remove affected areas and burn them to prevent further spreading. 


Affects many types of Bonsai and can be described as abnormal outgrowths on plant tissues and can be caused by fungi, bacteria and parasites.

If you discover these abnormal outgrowths on your bonsai, cut off the affected portion and try spraying a Bordeaux mixture or copper fungicide.

To help avoid Galls, provide your Bonsai with good ventilation in a spacious area.

There are plenty of well known Insects and Bugs that will hinder your caring for Bonsai plants by stripping off leaves and shoots, or damaging bark and branches. Such as:

• Caterpillars

• Grasshoppers

• Ants

• Slugs

• Snails

• Wasps

• Spiders

• Grubs

• Worms

• Ladybugs

• Praying mantis


Rodents can also damage your Bonsai by digging up soil in pots and leaving waste. Wire netting or fencing may be required. 

It is important to the health of your bonsai that you control plant predators by destroying them psychically, or by spraying with insecticide.


When caring for Bonsai plants, ensure you are able to identify and solve problems and you should be up there with the masters!

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