Seasonal notes from Alex
Spring
...is a very busy time with fluctuating weather. Hot days cold nights with windy periods. With this in mind, it's best to pay close attention to the trees needs. Adequate water must be provided to ensure the tree does not dry out, particularly trees that have been just repotted. The new growth develops very quickly and is very soft and does suffer from heat stress very easily. Avoid the wilting of the new growth. It does result in cell death and the tips blacken.
Watering
Watering should be done every two days however keep in mind October and November the weather does get gradually hotter. As a result, you could be watering almost every day. Be mindful of the days when the weather is rainy. Sometimes it is only surface that is wet and underneath it could be drying out. You should check the soil every day or two days to ensure that it is still wet, even trees on a watering system. The drippers may not offer the right coverage and water only sections of the tree; some roots may get plenty and other roots not much at all. I advise changing the drippers around the tree every week or so and rotate the tree, so it is not in the same place all the time. Spring is not the time to be complacent. A lot of things are going on. If your trees are drying out too quickly, you can move it to a shadier area. If you are going away on holidays, ensure the person who is looking after your trees knows what they are doing and can be trusted with your bonsai. If you have any doubts, give them to your bonsai nursery to look after or a fellow bonsai enthusiast/gardener.
Position
Place your tree in an open area that optimally receives morning light and avoids the afternoon sun. If that cannot be avoided, then it is best it receives sunlight regardless of the quality. I think it is underestimated how much sunlight is influential to a certain tree. Place a conifer or pine in full shade and you can see the needles become dull and elongated. Then look at certain deciduous trees burn by having them placed in an exposed and full sun environment. Ensure the tree is rotated every couple of weeks. This way the tree gets even growth and not become lopsided. This effect is called phototropism.
Fertilising
I like to use organic fertilisers as much as possible. At present, I use low nitrogen fertiliser to boost the buds and roots as a fertiliser. For natives, I use Neutrog Bush Tucker every six weeks. Please note many organic fertilisers do smell and will blacken your moss. Fish emulsion fertilisers are great and can be used on natives.
For a longer lasting effect you can use slow release fertilisers which does the same thing except over a long period of time. Remember that seaweed concentrate is not a fertiliser and does not have an N.P.K ratio. A product which will denote N.P.K is a fertiliser. Regardless of product, please read instructions always before use.
Pests
Aphids on your new shoots need to be kept in check ensure they are sprayed with Eco-Oil, Pest Oil, Sharpshooter® complete insect spray. Read the instructions before use. Caterpillars on your figs eating your new shoots can be a problem. Treat by picking them off by hand or use Neem oil and spray on contact. Spraying randomly and hoping for the best is not the best approach. If you see any silvery/black shiny colour on your azalea especially under the leaves, your tree may be infected with Azalea lace bug, a very serious and damaging bug. It needs to be sprayed with Sharpshooter Complete Bug & Insect Spray or use RICHGRO Bug Killa straight away.
Re-potting
The re-potting of deciduous trees should be completed by now and should not be touched unless it is an emergency until March/April next year. Native plants repotting should be done around now. Flowering trees should be re-potted after flowering. If the health of the tree is an issue plucking off the flowers to concentrate on foliage should be considered. By November the season for re-potting flowering trees should be slowing down. If it needs to be done, try to cut less roots as the weather heats up. I have noted the pruning and the severity of how much the roots should be pruned is proportionate to how hot and how cool the weather gets.
Wiring and Pruning
Now is a good time to correct the growth of your trees by pruning and wiring your trees. Try and notice the strong growth areas and the weak growth and you can try and correct these branches by pruning harder at the stronger branches and lightly pruning the weaker branches. Pluck the juniper tips with your hands. A common beginner’s mistake is to trim the tips of your juniper with scissors. This scars the edge of the juniper with a red line that takes a long time to fade away. I recommend asking your teacher this technique as it will vary depending on the age and location of the foliage on the tree. Remove your azalea flowers if they are spent. This is called "deadheading". You can do this by plucking with your hands or carefully snipping with your scissors.