Bonsai Maintenance Calendar
Do you know the bonsai maintenance required during the different seasons? Learn how to take care of your bonsai tree all-year round with the help of our handy bonsai calendar.
From pruning to training and repotting, find out what tasks you need to carry out seasonally to keep your tree healthy.
How to Time Bonsai Maintenance?
To keep your bonsai happy and healthy all the bonsai tree maintenance you carry out should be done at a time when it won’t disturb the tree’ natural cycle. Causing excessive stress to your plant can be bad for its growing process and can slow it down, so timing your work accordingly is essential.
If you want to get the best results, it’s important that you work on a tree that’s healthy to begin with. Withering plants don’t react well to stress, which can put them at risk of dying completely. In order to ensure your tree is strong and healthy, you need to fertilise it the previous year as trees store nutrients to use the following growing season.
Understanding a Tree’s Yearly Cycle
During the year any bonsai tree goes through six different phases:
- Winter dormancy
- Spring awakening
- Producing new growth
- Short summer dormancy
- Strengthening of the new growth
- Preparation for winter
The length of each phase will depend on various factors such as the length of the daytime as well as climate conditions, which can affect the periods of growth and rest. For instance, high temperatures for longer periods of time can slow down or even inhibit the growth of your bonsai which will lead to the tree going into a period of dormancy that will continue until its normal environment is restored.
When to Carry Out Tree Maintenance Tasks
The best time to complete maintenance tasks on your tree without interfering is usually dependent on the species natural life cycle. For some tasks such as pinching buds you might be limited to only a few days, while other tasks can be carried out over a longer period of time either by adapting the procedure or taking a different approach that will benefit your tree more. An example of this is repotting broadleaf trees in summer instead of early spring.
Bonsai Maintenance During Winter Dormancy
During the winter months dormant trees are inactive due to the lack of sunlight and low temperatures. They don’t have need of light or fertiliser as there are no leaves to allow photosynthesis. During this period stick only to routine maintenance to prevent possible fungus or insect infestation.
Although there is no growth, however, the roots of your tree still need water in order to not dry out. Keep the soil lightly moist, but take care to not overwater your bonsai. With no leaves to help absorb the moisture, you risk causing the roots to rot due to excessive moisture.
The winter period is a good time to tackle a number of bonsai maintenance tasks, starting with repotting and pruning. Most bonsai species can be repotted in early winter, but the best period for it is the weeks right before the early spring awakening, when there is no longer a danger of frost. If you’re repotting your bonsai in winter remember to put it in a place safe from frost.
When it comes to pruning the branches of your tree, winter is a good time to do structural, replacement and maintenance pruning.
- Structural pruning is done to give a tree its initial shape, cutting back the length of the trunk and removing any unnecessary branches.
- Replacement pruning is intended to reduce the length of a bonsai’s branches or shorten its overall length. This is done by leaving a smaller secondary branch that will replace the longer one you cut off.
- Maintenance pruning is commonly done on older bonsai trees that have already been shaped to maintain their form.
After pruning your bonsai tree we recommend using bonsai cut paste or adhesive tape to seal the ends. This stops any bacteria or fungi spores from entering and also helps your tree retain moisture in the branches.
Spring Awakening and New Growth
At the start of spring, you have to carefully inspect your broadleaf bonsai to spot the first signs of new growth. Some types of bonsai such as the Chinese Elm should be left to bud without intervention. Only after the new hoots have developed four to six leaves should you cut them back after the second leaf using bonsai scissors.
In the case of bonsai that have already been styled, however, you need to cut back the new growth as soon as possible in order to keep it under control and maintain the elegant shape of your tree. This is particularly important for Japanese Maple bonsais, which if left unattended during their growing period produce straight thick shoots that can reach a metre in length.
With the intense growth in spring, you might have to pinch new growing leaves to refine the shape of your tree. It’s also the best time to take cuttings or start training your bonsai.
Due to their intense growth rate many bonsai species such as junipers or maples need daily maintenance. This involves opening the first two leaves in the new buds and removing the other leaves inside. This process is known as “pinching” and it promotes the growth of smaller leaves that sprout from the axils of the remaining leaves.
The branches your bonsai grows in spring are flexible, which means if you want to style and shape your tree, this is the perfect time to do it. If you’re using bonsai wire to change the shape of your tree we’d recommend starting this in early spring right before the start of the rapid growth.
Summer Maintenance
Summer is the second period in the year when you should consider pruning or repotting a bonsai tree. You can also come across summer dormancy. If you missed the ideal repotting period at the end of winter, you can normally safely repot some species of bonsai in the beginning of summer, usually in June.
Summer repotting is best done when the leaves of your tree are mature. You can spot mature trees by examining their colour and texture. Fully developed leaves are darker in colour and feel more resistant when you rub them between your fingers. When repotting in summer you should only cut back the roots by about 40% so you don’t disturb the water balance in your tree. Similarly, it’s also advised to cut back the foliage. After repotting it’s also important to keep your tree away from direct sunlight and wind for at least a few weeks.
As temperatures start to get higher in summer, it’s common to encounter a short period of summer dormancy as all plants slow or even stop their growth. All processes that the tree goes through from photosynthesis to transpiration go through major changes which leads to the plant adapting mechanisms that can reduce heat absorption.
During this period you need to pay careful attention to watering. The hot temperature and wind can dry the soil quicker than usual which means your tree will have to be watered more often.
You can spot this by looking at the leaves at your tree. If you notice the outer edges starting to turn brown and dry, then your tree needs to be watered as soon as possible. Otherwise the leaves will dry out completely and you want to avoid this.
If your tree’s water balance is disturbed for a short period of time, you can quickly re-establish its normal conditions by watering it regularly and sufficiently. Photosynthesis and growth may be inhibited temporarily, but no permanent damage will occur.
Autumn Bonsai Tree Maintenance and Winter Preparation
In autumn you should focus on fertilising your tree. Once the hottest months of the year are over, in late August to early September, plants resume their normal growth activity for a while before starting to prepare for winter. During this period you need to focus on fertilisation as your tree will need nutrients needed to develop new growth, replenish exhausted supplies and strengthen itself enough to cope with the cold in winter.
It’s advised to use fertilisers that are low in nitrogen, which encourages vegitative growth, and high in phosphorus and potassium. Both of these chemicals are good for stimulating root growth, strengthening the root system and helping the tree build enough reserves to last until spring.
At the end of autumn it’s time to start preparing your bonsai tree for winter. This involves choosing a suitable place to store your outdoor bonsai, removing dead leaves on broadleaves and removing old needles on conifer trees, and treating the branches and trunks to prevent fungal infections and diseases.
It’s important to remember that every tree is individual in terms of its needs, so bonsai maintenance on a schedule is close to impossible. To ensure your tree remains healthy and flourishing, the best approach is examining it regularly while keeping in mind the rough timing of all natural processes a tree goes through.
Finding the Perfect Tree with Bonsai 2 U
Whether you’re on the look for a new tree to add to your collection or a beginner enthusiast looking to get their first tree, at Bonsai 2 U we have a tree to match your needs. With a fantastic range of indoor and outdoor bonsai trees for sale both online and in-store, you certainly won’t be stuck for choice.
Browse all our trees today or if you need more care tips visit our Care Hub.