Bonsia Society of Australia inc.

And now an Introduction to this months presenter
 
SUE BRENNAN

A few tips for these hot summer days. Keep your Maples under shade to avoid burning of leaves by heat and wind. Immersing pots in water on a regular basis helps keep plants in good condition. When watering on hot windy days, mist all foliage and surrounding area of trees to create a humid condition. Don’t forget water pots thoroughly. I have even had Junipers that have suffered from burning of the foliage tips in the unusually hot weather we have experienced, one in particular was close to a brick wall and I suspect it suffered more because of the reflected heat off the wall.
 
There is still time to defoliate or re-pot figs, whilst larger leaves can be removed from most trees on a continual basis. Pinch out growth tips on such trees as Japanese Maples to promote back budding and thus ramification, any burnt leaves can be removed and it is also an opportunity to partially defoliate to allow new leaves to develop, but don’t leave it too late in Summer and be sure to protect your tree afterward.
 
Black Pine branches which have matured since forming in the Spring may be cut back by half to encourage more compact budding. Do not cut back where there are no needles.
 
Stand Wisteria in dishes of water as  this will promote flower development and root growth.
 
Keep up your established fertilising programme all through the summer, but do not fertilise in extremely hot weather. Remember, with extra watering fertilisers will leach through the soil at a faster rate than usual.
 
Hold caterpillars at bay with suitable recommended sprays and be careful of your Azaleas which can be damaged by Lace Bugs
 
Paint jins and shari with lime sulphur, but avoid touching living parts of the tree, soil or the pot.
 
Be careful with any wiring on your trees as it can cut in very quickly in a strong growth period as we have just experienced.
 
Pruning to shape can continue through Summer but remember to leave Winter and Spring flowering plants such as Crab Apples and Azaleas to grow as pruning will remove the flowering wood of the tree.

Our demonstrator for the October meeting last year was Ray Mackaway and he let us peek behind his peat moss and plastic covering to reveal how he performs his magic on trees with suitable trunks or branches for layering.  He has found that his new aerial layering technique has also been successful on trees that have previously been very difficult to layer e.g. trident maples, black pines etc.

Air layering is believed to be of Chinese origin and has been practiced for over 1500 years. Initially the method was to encase a partially severed branch in wet clay and then cover with hessian, the interruption to the sap flow causes the trunk or branch to go into survival mode and either bridge the gap or throw out new roots to draw moisture and nutrients from the immediate environment.

The advantage of air layering is that a mature tree can be obtained in a relatively short time. Detailed below is Ray’s layering technique.
 
METHOD
1. Ring bark the tree using a clean and very sharp knife. Cut then scrape a band 1.5 times in width of the diameter of the trunk, removing all cambium, to the heartwood.  Consider also the angle of the cut as this will form the new nebari and will of course influence the angle of the new trunk, it could be anywhere from straight to possibly a 30 degree angle. Wrap this area with strips of cloth soaked in Seasol to keep the bark from drying out until you are ready for the next step.

2. Prepare a hormone mix:  Mix together Clonex Purple and Richgro Hardwood or Yates plant powder in a 50/50 paste. Using a small paintbrush, paint the mix on to the top cut. Using bonsai wire the same thickness as depth of cut, place wire around heartwood pushed up under and against top cut and twist ends to tighten, as a tourniquet.  Paint on mix again over wire.

3. Add a muck collar:  Using clay and cow manure, in a 50/50 mix, roll into a sausage and apply around the trunk covering trunk, wire and heartwood.

4. Cover with sphagnum moss.   Using a thick quality plastic, like a cut up ziplock bag, and tie wire, tie the plastic around the trunk, creating a large, blousie bag which is generously filled with sphagnum moss which has been soaked in Seasol for at least one hour. Tie top of plastic to trunk and also wrap tie round and round the plastic to ensure good contact between muck collar and moss. Cover with Alfoil, not black plastic, to reflect heat.

Aftercare:  If you can see condensation on plastic, moss is wet enough. If dry, use a syringe to re-wet with Seasol.  Cut off the aerial layer only after a substantial root system has formed. Cut through the trunk, soak roots in Seasol and then carefully tease out the new root system. Some people will plant the new section in peat moss rather than potting mix to limit the chance of damaged roots.

The more roots showing in the moss the greater the chance of the air layers survival. Plant, but do not fertilise until tree has recovered and is showing new growth, use only Seasol up to this point as fertiliser could damage the tender new roots.

In time it will be impossible to tell that the tree has been air layered as opposed to being grown from seed, cutting or grafting.