What to do In June
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What to do In June
Winter is here. And it’s time to prepare for pruning and repotting of your bonsai.
It is getting colder, and the rain season started (Cape Town) with lots of wind and rain.
For those that are not sure about what’s happening with their trees, keep in mind that deciduous trees (Acacias, Maples, Swamps, Elms, and White stinkwoods) will lose their leaves.
Tropical trees like Figs will also lose some of their leaves, mostly the older leaves.
Some trees of the same species can lose their leaves earlier than others. This is influenced by time of defoliation, position (warm protected areas, indoors, outdoors), pruning as well as disease.
General maintenance
Keep a watchful eye on your trees. Even though it is raining a lot, there are still dry spells in which trees can dry out. Even though some of your trees may be dormant they still need water to survive. See that trees standing in protected areas, like patio’s etc., get enough water. Often placing trees near or next to your house to protect them from the wind can result in them not getting any rain and they will dry out.
Protect your trees from the wind. Strong winds can blow your trees off the shelves, breaking branches and damaging pots. Tie the trees to the shelves with wire or rope.
Make sure that your bonsai pots drain properly. Often the drainage holes can get blocked by snails (remove them from the drainage hole) or by the activities of earthworms breaking down the organic matter in your soil mix (use a stick to open the drainage hole without disturbing the roots). If your pots do not drain properly tilt the pot and place something under it to help drain water from the pot. If your bonsai’s soil does not drain well, it is an indication that you need to repot it in the repotting season.
Remove dead leaves from your pots. They only create a place for bugs and diseases to hide.
Remove moss from trees with soft bark, like cork bark elms, acacia etc. Leaving the moss on the trunks will cause the bark to rot. Also remove moss from the soil. Moss retains a lot of moisture in the soil which can cause root rot on trees like olives.
Do not throw the moss away. Place it in single layers in shallow containers under the bonsai bench. You can use it in landscapes etc.
If need to moss can be killed by spraying it with vinegar and then carefully removing it with tweezers.
Place baobab and Adenium species (impala lilies) in a protected area with good light and keep dry.
Remove your trees from the shelves and clean the shelves of old leaves and dirt. You can also disinfect the shelves with a strong Jeyes fluid mix. Place it in a spray bottle and spray the benches with it. Only replace your trees on the bench after the smell has faded.
Some trees like Azaleas will flower from middle to end of June. Remember to remove spent flowers.
Pruning
Pruning can be done from the end of the month if you got a lot of trees and need to extend your potting and pruning period. Rather wait till early July before pruning. Trees need their rest and by pruning them too early you place them under unnecessary stress. (Thousands of wine farmers can’t be wrong)
Do not forget to seal bigger cuts with a tree seal or cut paste.
A lot has been discussed regarding the autumn pruning of deciduous trees. Most of the discussions are from overseas countries where they have several diseases that infect species like maples through open wounds when they prune in spring. In South Africa we do not have these diseases yet and pruning can still be done until mid-August, as long as the sap did not start to move.
If you plan to prune in Autumn, only do so after the leaves have changed colour and start to fall off. Pruning earlier and the tree can start budding again with the hot spells we get in Autumn. The tree uses a lot of energy to produce these buds, which will die later in winter. The tree also recovers a lot of energy from old leaves before discarding them.
Fertilizing
Do not feed deciduous trees, but evergreens showing growth can be fed.
You can feed your pines and junipers. A good fertilizer for junipers and pines are liquid fertilizers like Nitrosol, Go Organic, or slow-release fertilizers like Bonsai Boost.
Repotting
Bonsai have been potted in South Africa in a mixture of compost and stone/river sand etc. for many years and many fine good quality bonsai can be seen around that has been planted in these mixtures. It is still a good mixture and economical if you keep to the basic requirements of a plant.
Hydroponic growers have been growing bonsai in plain gravel, plain wood shavings, or even without soil, successfully, because they kept to the basic requirements of the plants.
Do a bit of research on soil mixtures so that when repotting season starts you can be prepared to make informed decisions when potting your trees, and you can make corrections to trees that needed a change in their soil mixtures. Try to keep your soil mix out of the rain. (Do not pot with a soggy soil mix.)
Do not pot any trees at this stage. Start preparing your soil mix for the repotting season.
Early next month you can start with potting swamps, white stinkwoods and at the end of the month, elms.
If you plan to make your own soil mix keep the following in mind.
- Your mixture must support your bonsai tree until the next time you plan to pot it. Where ‘support’ means keep the tree in position, hold enough water, keep the tree alive, feed the tree and keep a healthy root system.
- It should be free draining, not retain too much water, causing problems like root rot.
- It should be able to retain enough moisture until the next time you can water (most of us work away from home for at least 8 hours).
- Do you plan to add organic material to your soil – i.e., compost, peat, etc.
- Do you plan to use nonorganic materials?
Just to mention a few materials that you can use for your soil mix.
- Compost – Use a good quality compost made from composted pine bark or chipped wood. Do not use mushroom compost. Mushroom compost breaks down to quickly and clog up you soil mix.
- Grid – many options are available – Do not use fine sand. Again, it will clog up your soil mix and prevent good drainage and aeration of your mix.
- Leca – Leca is a porous baked clay medium, that will not break down, gives good drainage, has a neutral pH, will retain water without being too wet, will retain food for your tree, and its light – it floats on water.
- Akadama – It’s balls of volcanic clay that have been mined and naturally dried or baked to the desired hardness – read more about it here https://bonsaitonight.com/2016/07/15/all-about-akadama/
- Pumice – It’s volcanic rock that a textured volcanic glass –
- Lava rock – It’s volcanic lava that cooled down. It does not break down.
- Charcoal – Made from various materials its basically carbon in solid form
Many bonsai growers are using akadama and some are the proud owners of imported trees planted in an akadama mix. Keep track of the condition of the akadama. Akadama break down over a period of time. Akadama breaking down (over a period of years – depending on the type of akadama) help with the refinement of bonsai, i.e., reduction of leave size etc. But the downside is that because of the breaking down process watering needs to be monitored and controlled. Since it is a widely discussed topic with many different opinions I’m not going to go into the processes in this article. Search the internet or speak to experience bonsai growers regarding the use and effects/properties of akadama.
Follow the link to Boon’s bonsai mix, one of the more popular bonsai soil compositions. You will also find an explanation on lava rock, akadama, charcoal, granite, etc. – https://bonsaitonight.com/2010/10/01/bonsai-soil/
Follow this link to Michael Hagedorn from Crataegus bonsai mix https://crataegus.com/2009/02/10/its-repotting-time/
And an explanation to the different between lava rock and pumice by Michael – https://crataegus.com/2009/02/23/lava-woes/
Pests and diseases
Deciduous trees that already lost their leaves can be sprayed with diluted lime sulfur. Mix the lime sulfur with water in a ratio of 1 part lime sulfur to 30 parts water. This mixture ratio won’t stain unglazed bonsai pots much. You can use much stronger mixtures, but it will stain unglazed pots (for stronger mixtures read the manufacturer’s label).
Spraying deciduous trees with lime sulfur while they are dormant will kill off unwanted pests and their eggs as well as other diseases. Lime sulfur will also help with the control of fungal diseases like anthracnose. Cover unglazed pots when you spray the trees with something like glad wrap to prevent the lime sulfur from staining these pots. Repeat the spray after 10 days. Lime sulfur can burn/damage new growth. Lime sulfur breaks down over time and for the best results purchase new lime sulfur every year.
Spray your olives with a preventative spray for root rot.
Styling and design
You can now needle pluck, design, and prune your Japanese black Pines.
Junipers can be wired, pruned and styled. Now’s a good time to do large bends on Junipers. Wrap branches with raffia to protect them during the bending process. If you are not sure on how to use or apply raffia, ask experienced members of your club or a bonsai nursery.
Be careful when you wire trees this time of the year. Branches are very brittle and can break easily. Be careful when bending branches.
Start shopping around for new potential bonsai stock. Most of the trees in nurseries have already stopped developing and are only putting down hard wood, increasing their trunks. Shop around to be first to find the best stock.
Also read up on and start to prepare yourself for the following ideas to improve your bonsai (And some advertising)
- Improving the nebari (root base) on your deciduous trees (read about root grafting here). Start looking for suitable rootstock, cut paste, etc.
- Improve your branch structure on deciduous trees and figs with thread grafting. Get suitable material, wire, cut past ready.
- Plan grafting of different Pine species on each other. Like White Pines on Black Pine stock, Mugo Pines on Black Pines, Etc. You will need Root stock, Grafts, Grafting tape, Grafting knife, etc.
- Also prepare yourself for propagating new stock, sowing seeds, taking cuttings, etc. You will need vermiculite and/or perlite, plastic training pots, rooting hormone, etc.
- Sharpen your pruning tools and sterilize them.
Another topic that I need to discuss: Feeding of sick or stressed or newly repotted trees.
Trees manufacture food from ‘dissolved chemicals’ (what we call ‘plant food’) that it absorbs from the soil (process of osmoses). The tree then transports it to the leaves where the tree makes use of sunlight to manufacture food from these ‘dissolved chemicals (photosynthesis).’ This food is then distributed to the rest of the tree on which it feeds and grows.
Trees are NOT like human beings whom you feed chicken soup too when they are sick to get their strength back. Trees make their own food (photosynthesis). But a sick tree, newly repotted tree or stressed tree cannot take up these ‘dissolved chemicals’ if they are sick or under stress (osmoses). We often like to give trees human qualities/characteristics and want to feed sick or stressed trees back to health. It does not work like that. Feeding sick or stressed trees will only increase the ‘dissolved chemicals’ in the soil. Adding more dissolved chemicals (‘plant food’) into the soil will cause a process called reverse osmoses which will further damage the tree. This also goes for foliar spray/feeding.
Plant food as we buy it from the shops is not “food” for plants. It is part of the chemicals necessary to produce food, which only the tree can change through photo synthesis into food.
Without leaves the tree cannot make use of the process of photosynthesis to manufacture food and all the ‘plant food’ that you feed your trees will wash away or accumulate in the soil.
In short – do not feed sick or stressed trees, newly repotted trees or trees without leaves. There are a few chemicals that can be applied to help stressed/sick trees but first ask an experienced grower before applying it to the tree.
Also read up on the following products that help sick or stressed trees:
Kelp extract products like Kelp from Wonder help with the forming of healthy roots.
Vitamino is specially formulated to help with stressed trees like sick trees, repotted trees, etc.
Bioroot also help to stimulate root development
Again – Do not feed sick or stressed or newly repotted trees.
Stephen
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