What to do this month

Updated 2019/12/01

Summer is here and the days are hot, dry and windy. This means that you need to water your trees regularly, up to twice a day. Look out for problems in watering systems (blocked sprayers, etc.), protect trees from the wind and place sensitive trees in protected areas.

Wind damage the leafs of Maples and White Stinkwoods this time of the year and if possible place them in a shaded area out of the wind.

Mame trees can be placed on humidity trays. This can be made from drip trays filled with river sand or gravel. Put enough water in the drip tray to the level of the gravel/sand. Then place the mame on the gravel. Do not let the pot stand in the water. If the pot is placed in the water it will cause root rot on the mame. The idea is for the water in the drip tray to form a more humid environment around the tree. Several mame can be placed on the same drip tray.

Keep track of wire on your trees.

It’s also holiday season and time to go away on holiday. Plan where you are going to keep your trees. If you get somebody to water your trees for you over the holiday period, ask them to come to your place and let them water the trees two or three times with you so that they understand how much water are needed and what your basic watering routine is. You can also contact your nearest bonsai nursery and ask them if they offer a boarding service looking after your tree over the holiday period. Every year you will hear that people lost trees due to persons who were suppose to care for their trees did not water the trees properly and several trees died. (With Murphy involved it’s usually the best trees that die) Trees are not always killed by a lack of water but also by too much water. If you plan to make use of an automatic watering system install it at least two weeks before you go on holiday so that you can fully test the system before leaving your trees in the care of a computer. Get a friend to regularly check up on your watering system.

Growth on the trees slowed down and now is the time to catch up on your pruning. Fertilize your trees on a regular basis. Basic plant food can be used to fertilize the bonsai. Just be careful that you don’t give the tree to much of the plant food. If you are not sure ask a local nursery.

Maples and White Stinkwood can be defoliated. This will help to replace leafs damaged by the wind, will force the tree to produce smaller leafs and also give you the opportunity to work on your development of the tree, prune unwanted branches and wire were necessary. Just remember that if you decide to defoliate a tree to reduce the size of the leafs, do not feed the tree for at least two months after defoliation. Feeding it will have the result of bigger leafs. Do not defoliate a tree that’s not healthy. When your tree start to push new leafs (around two weeks after defoliation), place the tree in an area protected from the wind, or the leafs again will get damaged.

Figs can still be repotted.

Do usual maintenance pruning, pinching back new growth and developing the tree.

Insects and pests are very active at this time of the year. Keep them under control. Remember, poisons are dangerous. We all got family members coming to visit over the holidays. Keep small children away from poisons and when you like to show everybody your tree collection, warn them not to touch the trees.

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. Look for white fly on the underside of the leafs of Olives. Spray your olives with a preventative spray for root rot.

Prune Elms by constantly pruning the new growth back to 2 to 4 leafs. Make also use of the clip and grow method to develop the tree. Remove unwanted growth on your Elms. Choose the branches that you need to develop on new trees and remove the rest.

During December you can de-candle your black pines. Only de-candle healthy pines.

Weeds also tend to grow fast this time of the year and can become a problem.

And for the Cape Town growers struggling with the drought, a few watering tips.

Place your bonsai in an area where it get only a few hours sun, preferably in the morning or place them under 40% shade cloth.

Cover pots to prevent the sun from heating up the pots and drying out the soil. You can make use of hessian, netting, tinfoil, etc. Anything that will keep the pot cool will reduce the water loss.

Place mulch, chipped bark, moss, or extra compost on the soil surface of your bonsai. It will help to keep the soil cool and prevent evaporation. Don’t use lawn cuttings.

In extreme situations you can ‘plant’ your bonsai into the soil with the pot. This will help to cool the pot and reduce evaporation. When winter comes and the rains start you can remove the tree with the pot from the ground. Or place your bonsai pot into a bigger pot.

These ideas will not be the best way to show your bonsai, but it will reduce the tree’s water usage and help it survive through the drought.

When making use of borehole or well point water, have the water tested before giving it to trees that are sensitive to salts. Most people would tell you that their water is ‘pure’ and ‘can be bottled’, ‘it contains no salt’ or ‘that you can drink it’. Several trees are very sensitive to even the smallest quantities of salt diluted in water. Borehole and well point water often contains salts due to the presents of different types of water solvable ions in the ground. Salts do not only mean table salt but can include several types of metals like iron. It’s often not possible to taste these salts.

These salts start to build up in the bonsai pots due to evaporation where the water evaporate, leaving the salts behind, and with every watering you basically add more salt (think of the old school science experiment where you placed salt water in a saucer to evaporate the water and to form crystals) During normal watering these salts will be washed out of the soil with the water running out the drainage holes, but with the drought everybody just water enough to keep the soil moist and for the trees to survive. Also test the water’s Ph. We’ve found that the ph can differ quite a lot between different boreholes, again affecting the trees.

Try not to use grey water containing soap on your bonsai.

And the most important tip is to get rid of all the hundreds of potentials in black bags that’s been dragged along for years for the ‘One Day’ (probably never) project. Rather get rid of it, plant it in the garden, or turn it into compost and save the water for all your real bonsai. You will also find that you will have more time to spend on developing your bonsai, time that would have been wasted on maintaining these ‘One Day’ projects.

Its time to start working on your pines. If your pine is in refinement stage you will need to decandle your pine during December. If you do not understand how to contact an experienced bonsai grower. I’ve attached several links to articles written by Jonas Dupuich from bonsaitonight.com on growing Japanese black pines. Remember to only use one experienced grower/teacher to guide you on how to work Japanese black pines. Ask them first to see their pines before you decide to follow their methods. There are many different articles on the internet and written in books that describe many different ways. Each may work on its own but combining them will only damage and possible lead to killing your Japanese black pine.



Description of different types of buds on black pines


How to cut back instead of decandling






How to stimulate back buds on black pines

Ryan Niel from Bonsai Mirai also did several videos on Japanese black pine as well as Peter Tea. Don’t try and combine their methods. Use only one method.

Also visit our face book page at ‘Stone lantern bonsai nursery’ for more articles, photos and events.  Please feel free to make suggestions on how to improve the page and what you would to know more about.

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