What to do this month

Updated 2018/10/01

The weather is getting warmer and everything is growing strong.

Remember aftercare is the most important part of repotting.  You can do the best job in repotting the tree but only one warm day in which your tree is not protected from the heat or wind will kill your tree.  A good after care spot will be a cool, protected (wind and sun) area, where the tree will get enough water.  The soil must not be too wet, neither must it dry out.  I prefer to give a light spray on the foliage of newly repotted trees several times a day for the first three weeks, only watering the soil when necessary, trying to keep a moist environment around the trees.  Also make sure that your tree is stable in its pot.  If the tree appears to be a bit loose in the pot, while you are potting it, tie it down with wire through the bottom of the pot.  Just remember the wire on the tree.  You will need to remove it later when the tree formed enough roots to support itself.  Leaving the wire on for too long can damage the roots, even kill them.

Trees like Acacia take a long time to form new roots, and in places like Cape Town with its wind you need to keep then tied down or in a protected area for long enough to form enough roots, or you will find a lot of slanting trunks in your collection.

Newly potted trees still need to form new roots to keep up with the demand for water and food. Do not move your newly potted trees out of the shaded/protected areas before the tree show strong signs of growth, (i.e. if you are not sure at least growth of over 5 cm). Then gradually move the trees to more exposed areas over a period of several weeks.

Celtis, Maples and Elms are growing very fast this time of the year and weekly pruning is necessary to keep the tree in shape and to develop the tree. Watch your Maples as the fast growth can cause rapid increase in the internodal lengths, spoiling the ramification of the tree.

Control the new growth on Maples by breaking out the growing tips.

There is an alternative method of growing maples. Go and look at the blog of Walter Paul regarding his hedge cutting method. Look at these links



Remove unwanted growth on your Elms. Choose the branches that you need to develop on new trees and remove the rest. Newly potted Elms will start off with an abundance of new growth/buds all over the tree. Choose the buds that will fit in with the design of your tree and remove the rest by rubbing them off.

When developing the ramification on a young elm, or white stinkwood, a useful “cheat” that can be used to keep the development of the tree uniform is to prune the branches in the top part of the tree back to one set of leaves while two sets of leaves can be left on the branches in the bottom part of the tree. This will insure that the bottom part of the tree will increase twice as fast as the top part, developing the triangle of the tree. This method will not have any significant effect on the development of the ramification of the tree, but can shorten the development of the triangle of the tree by several years, as long as the intermodal lengths are kept under control.

Remove spent flowers from your trees like Azaleas and Wisteria and plan the fruit on your fruit bearing trees. Remember that fruit on bonsai seldom can be reduced in size like the leaves. Allowing too many fruit to develop on a tree like for instance, a pomegranate can result in some dieback on some of the branches. The tree will go into a self preservation mode, ensuring the development of the fruit for the future of the species, to the cost of its own health. Pomegranate often will shut down all other development, branches dying back, to ensure the survival of the fruit.

Due to the winter rains a lot of the nutrients in the bonsai soil was washed out and need to be replaced. I personally do not like to feed my trees in the first two months of spring, due to the fact that they normally show strong growth and that feeding, especially with a fertilizer with a high nitrogen content, can increase the growth and with it comes bigger leafs and longer internodal lengths.

Fruit bearing trees are now in flower and feeding them with a fertilizer with high nitrogen content will cause them to stop developing the fruit and probably dropping the fruit right after flowering.

However, I do feed my Swamps, Wild Olives and Junipers this time of the year regularly to develop the trees and to make use of the growing season. Feed with Nitrosol, Seagrow, or Bounce back, or any other plant food. Read the pamphlet for feeding recommendations for potplants and then use half the strength for bonsai.

Watch the wiring on your trees. I’ve noticed that the wire started to bite into the bark of several Maples and Swamps.

Be careful when you want to wire and bend Pines and Cedars. The bark/cambium develop very fast this time of the year and if you twist the branches to much you can break the cambium off without any visible signs of damage to your tree, only to find a few weeks later that your tree die due to unknown reasons.

You can still repot Junipers and Acacia. Remember to wire the trees in the pot when repotting Junipers and Acacia. The Cape Town winds will blow these trees out of their pots.

Wild Figs can be potted from the end of October.

Pests are very active and need to be controlled. It’s important to look out for bugs and use the right insecticide to control them. If you are not sure ask your local nursery. Look out for red spider mite and Aphids and control with the necessary poisons.

Also look out for signs of Thrip on your Wild Olives. On the first sign of marks on the Olive leafs spray your trees.  Preventative poisons, like Merit, can be used to control pests for long periods. Look for white fly on the underside of the leafs of Olives. Spray your olives with a preventative spray for root rot.

Watch your Junipers for signs of grayness which usually indicate mites. They can kill your Juniper in a matter of weeks.

Weeds also tend to grow fast this time of the year and can become a problem. Use Snapshot to stop the germination of seeds. (Just remember that if you are going to use snapshot in your garden it can influence the germination of future flower seeds.)

Wait till your Boabab show proper growth before taking it outside and start to water it.

Wild Olives can still be collect from the wild with the necessary care.

The last of the wild olives collected this year have started to push new buds.

And last but not least. Keep track of moss on your trees. If you notice that the moss start growing up against the trunk of especially trees with corky or flaky, it should be removed. Moss will cause the bark to rot and it will take years to replace the lost bark.

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