Spring

september, october, november


September

With September comes Spring and warmer weather in most parts of Australia.

Your deciduous trees should have been root-pruned already as this seasons new growth will be showing. Australian natives may be ready for root pruning now however their roots should only be touched before a growth spurt and during bud swell - so check first.  Figs shouldn't be root pruned untill the weather really warms up and flowering plants like Azaleas, Camellias and blossoms shouldn't be re-potted or trimmed until after their flowers drop.  Japanese Black Pines and other members of the black pine family (Red Pine, Scots Pine etc) should be repotted during this month before the needles have appeared from the candles. Some other evergreen exotics like the Olive, Cotoneaster, Pyracantha and Buxus can also be repotted in early September. Junipers can be repotted now however they have a longer potting period of well into Spring.  Remember, root pruning gives your tree the ability to grow a compact root mass and gives us the ability to keep them healthy in small pots.  Don't neglect your repotting and root pruning as a pot bound tree will loose vigor - or worse, die.  After cutting or exposing roots use a tonic like Seasol to promote healthy dense growth.  Do not use on Banksia Species as they dislike seaweed based products and some deaths have been recorded.

Now is a good time to start preparing to plant any seeds you are planning to propagate.  Some native seeds need special preparation to germinate so check our species guides for tips.

Don't forget to keep a close watch on your wired trees, particularly branches showing vigorous growth. Remove wire completely if necessary and be very careful not to damage the delicate new growth.

As the weather warms up you will need to increase watering and fertalizing as the new growth starts. Tree's that have recently been repotted should have had some slow release fertilizer mixed in with the soil however natives don't like phosphorous so use a specialist fertilizer like Osmocote for Natives. Supplement your slow release fertilizer with an application every 2 to 3 weeks of an organic liquid like Charlie Carp.

If your moss looks poor on trees that have not been repotted, replace it with a fresh lot.  Collect moss from damp areas or grow your own from purchased spores, it's not as hard as you may think.

A lot of varieties of trees will be full of fresh leaves and vigorous growth so now is the time to start pruning and tip pinching.  If your trees are young and need their trunk girth thickened allow the shoots to grow for a while before trimming back to 1 or 2 sets of leaves.  Trunks will not thicken without growth at the top of the tree.  For mature trees, snip or pinch the emerging leaves to maintain shape, reduce internode length and increase ramification.  Keep on top of your leaf trimming in Spring as new growth will get leggy quickly and internodes will become undesirably long.

And importantly, remember to take time to enjoy what spring brings - warmer weather, fresh new growth and beautiful flowers.

Tasks for September


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October

By the October, we are into the second month of spring, but in Sydney this can change according to your particular suburb or even in some instances your street. Book learning can be misleading to the point of each providing varying advice even to the point of contradiction.

Often with this misleading advice the plant dies just because you followed instructions: perhaps only your timing was wrong. Here in my area of the Sydney Hills district my plants have determined that we are indeed into the third month of the growing period whereas elsewhere the leaves may be just opening.

Many factors determine the plant dormancy & re-growth sequence. As Australia & other Countries have many time zones within their boundaries so also does Greater metropolitan Sydney varying from the mountains to the sea.

Most of us are aware that temperature affects re-growth but then so does light, which could be :-lengths of sunlight, the degree of light intensity as well as the duration of cloud cover. Any or all these factors will alter the dormancy & re-growth cycle. I put it this way the plant knows the timing better than we. Let us so be guided by our plant & have nature working with us not against us.

Towards the end of October the repotting of many of the other species of Bonsai is finished and in Sydney our next direction is towards the ficus species. The warm temperate varieties require consistent nightime temperatures not falling below 12 to 15 degrees for optimum results.

Results can differ if work is done prior to the above temperatures. This will depend on how drastic the pruning of roots and how much potting mix is removed. To rootprune out of season ie. when night temperatures are too cool: removing very little of the rootball is a waste of time. It is far better to wait and bare root. Figs can be treated as deciduous plants.

Pruning back branches to bare wood and the shortening of thicker primary roots will not kill figs, but the setback restricts their vigour. Figs repotted at a later stage are regrowing more vigorously than those repotted earlier.

The more tropical figs ie. F.macrophylla, F.benjamina sp. definitely respond to even warmer nights. Pruning during lower night temperatures can result in total or partial dieback of the branches so pruned.

Soft new growth on our bonsai in spring is an inviting target for aphids. They are accompanied by ants who ‘milk’ the aphids for their succulent sweet secretions. The spillage ‘grows’ the sooty mould, which causes the dermis (bark) and leaves to be coated by a dark furry mould.

The ants and aphids must be eliminated before tackling the mould. A mild insecticide such as pyrethrum is usually sufficient. Certainly no household ant insecticide such as borax should be uses on plants.

Subsequently, spraying or brushing with an old toothbrush with a mild un-scented laundry soap can eliminate the mould. Alternatively use a fungicide to treat the sooty mould.

By the calendar, we are into the second month of spring, but in Sydney this can change according to your particular suburb or even in some instances your street. Book learning can be misleading to the point of each providing varying advice even to the point of contradiction.

Often with this misleading advice the plant dies just because you followed instructions: perhaps only your timing was wrong. Here in my area of the Sydney Hills district my plants have determined that we are indeed into the third month of the growing period whereas elsewhere the leaves may be just opening.

Many factors determine the plant dormancy & re-growth sequence. As Australia & other Countries have many time zones within their boundaries so also does Greater metropolitan Sydney varying from the mountains to the sea.

Most of us are aware that temperature affects re-growth but then so does light, which could be :-lengths of sunlight, the degree of light intensity as well as the duration of cloud cover. Any or all these factors will alter the dormancy & re-growth cycle. I put it this way the plant knows the timing better than we. Let us so be guided by our plant & have nature working with us not against us.

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November

At this time of year in the Southern Hemisphere, soft tender shoots are often accompanied with aphids and other sap sucking, rasping or chewing insects, which can cause havoc to one's bonsai. Not only is the beauty marred but the vigour is retarded.

As foliage manufactures 'food' (complex carbohydrates) at night for plant stamina, removal of their source of supply can weaken a plant if it is not in vibrant health. The point of this statement is the remarks of some growers, and the printed material, advising people to spray the relevant insecticide to bonsai plants at half strength.

Does this mean the insects that attack bonsai are weaker than others, a special breed perhaps? NO! it is not so. Full strength insecticides do no harm to bonsai, only to the 'bugs'. Often an oil spray used in the heat of the day may burn the leaves.

The broad leaves of some Australian Native Plants (Eucalypts, Angophora and Lophostemon confertus formally Tristania) become blotched after spraying insecticides, especially pyrethrum, in sunlight although unsightly, it is not harmful to the plant.

A problem that I first became aware of was shown to me in New Zealand some years ago, and has mystified bonsai growers in some areas in Australia for some time now. I came across the solution to the affliction whilst researching a species. This particular problem occurs with the Juniperus cultivars and in particular the Juniperus procumbens Nana and possibly J. squamata Prostrata.

The problem shows up on the crown only as distinct to another blight afflicting the entire plant, but that will be next months tip. This particular nasty is called Phomopsis juniperovora, which causes the crown area only; to slowly, very slowly deteriorate.

Without treatment I suppose the crown will eventually and totally die. The tips become weaker & weaker and no amount of foliar feeding can improve the condition. The solution can be a problem though, because the fungicide Benlate was withdrawn from the general market following a huge lawsuit. The product has reappeared but can be sold only in 1-kilo lots at an expensive cost. Unfortunately it is the only fungicide available that will work. Now at least you know the name and what it does. If you have the problem it will cost you.

Although writing these tips for the Sydney, Australia region I am aware they are being read in sometimes vastly different climatic conditions. The timing for rootpruning in your area may differ from the time (August) that I suggest for Sydney. How to adjust your timing will depend on you plants'break of dormancy. Simply apply your timing for your deciduous Bonsai.

As the nights are becoming warmer in Sydney, the time should be beneficial for working with the Ficus family. Despite variations to the climate that makes a late start for the leafbuds to burst your plants should always be the indicators of the RIGHT time for them.

Often one hears of people afraid to root-prune their broadleaf evergreen bonsai, the plant is always in leaf! when then is it possible & safe to cut back the roots? Others can't understand why their broadleaf evergreen bonsai died after cutting the roots. The reason being the plant was already in new growth which of course: is too late.

Mature leaves on a plant do not indicate new growth, be aware though, with many plants it is safer to cut roots at the end rather than the beginning of dormancy.

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(Author: September Section written by Steven Hantos. October and November Sections written and kindly provided by Dorothy Koreshoff.)