For the Beginner - Summer Care of your Bonsai

by Viky Petermann

headerThe potting season has finally come to an end. You found it to be a mad rush, but you managed to pot all your trees on time. If you think that you can now sit back and relax, think again. The fresh soil in the pots and the extra space given to the roots have given a great amount of vigour to your tree. Now is the time to begin establishing the look of maturity of your tree and what you do now will depend entirely on the stage of development of your plant.



If you have a young plant, newly designed and with no primary or secondary branches established, then your aim is to develop this basic structure of the plant (Fig.1).

fig1Figure 1

Since the tree has been planted in a larger training pot, the growth will be very vigorous and soon it should have many small branches growing all over (Fig.2).

fig2Figure 2

Allow the branches to grow until their bases reach the thickness that you want them to be and then prune them back and wire them into position (Fig.3).

fig3_copyFigure 3

Repeat this process until your primary and secondary branches are in place.

For trees, which have already achieved this basic structure, the aim is to create as much fine ramification as possible. This is especially important with deciduous trees such as maples, elms, celtis and zelkova that are much admired in winter when they show off their silhouette. The best way to achieve this is by pinching consistently throughout the growing season. Allow a branch to grow 3 to 4 leaves or pairs of leaves and prune them back to the first or second leaf, depending on the direction of the growth desired (Fig.4), or the first pair of leaves where the buds will produce two new branchlets (Fig.5).

fig4Figure 4

fig5Figure 5

This should be done repeatedly throughout the growing season to build up the ramification of your tree.

If your deciduous tree is very vigorous and it has been well fertilized it is also possible to defoliate it in the middle of the summer. By removing all the leaves off the tree, the plant thinks it is coming out of winter dormancy again and it will put forth a new crop of leaves. This will allow you to pinch again with the result that double the amount of twigs will be created in one growing season. A word of caution, do not defoliate sick or weak trees and never defoliate evergreen trees, such as junipers, as these plants could die.

To make sure that trees grow vigorously and that they can respond best to the training techniques it is advisable to fertilize them regularly. It is best to start feeding the trees about six weeks after repotting with a fertilizer high in nitrogen to promote vigorous leaf growth. Fertilize every second week throughout the growing season, changing to a low nitrogen feed at the end of the summer, as the needs of the trees change from leaf production to the hardening of growth in Fertilize every second week throughout the growing season, changing to a low nitrogen feed at the end of the summer, as the needs of the trees change from leaf production to the hardening of growth in preparation for the winter months. There are two types of fertilizer to choose from, organic and inorganic.

Organic fertilizers are made up of animal and plant material while inorganic feeds are composed of different chemical elements, usually N (nitrogen) P (phosphorus) K (potassium), in different strengths so as to suit the different needs of the plants. Organic fertilizers are normally considered safer to use, as one does not run the risk of burning the tree if a dose of feed is too strong. Always water the trees before feeding them and as a rule avoid feeding newly repotted plants or weak and sick trees, because you could do serious damage to the plant.

If a tree's growing needs are met in terms of water, food, light and fresh air, strong healthy growth will result. However, even the best cared for trees sometimes get attacked by pests. The most common pests are aphids, mealy bugs, scale insects and spider mites. Your local nursery will have an array of chemical products designed to combat each specific pest. I find it best to isolate the infected tree and to treat it individually rather than spray all the trees on the growing bench in the hope of stopping or preventing the problem from spreading. Spraying poisons indiscriminately will kill both the pests and the beneficial insects alike. Helpful insects such as spiders, ladybirds and praying mantises, to name but a few, are what keep the pests in check under normal growing conditions and it is important to try to keep them alive otherwise the pests will multiply to unmanageable proportions.

There is no secret to creating mature looking bonsai other than the constant repetition of simple care techniques such as pinching, watering and fertilizing. These methods will, over a number of years, create the appearance of age in your trees. Don't be in a rush to establish tertiary ramification; make sure that the basics of your tree are in place. If you first establish the taper and the primary and secondary branches of your tree and only then do you try to achieve fine ramification, you will find that it won't be too long before you have created a tree which will give you great enjoyment.


Contact Us

We would be happy to hear from you should you like to find out more about the club, meetings or bonsai in general.

Send us a mail

Year Programme

We have an exciting calendar of club meetings, events and public exhibitions planned for 2017/8.

Learn more


Fearlessly he moulds and

guides the elm tree

to a greater masterpiece

Random Bonsai Tip

Where the primary branch is thinner than the secondary one, prune back the secondary hard, keep it trimmed back and allow the primary branch to grow unhindered until it has thickened.