Susquehanna Bonsai Club

The premiere bonsai club of south-central Pennsylvania


Mauro Stemberger – Susquehanna Bonsai Club

Sorry for the VERY LONG absence of updating this site. My time with 2 jobs, a family and everything else made time hard to come by. Going forward I promise to update this site regularly as I now have time to do so 🙂

Mauro Stemberger : Susquehanna Bonsai Club –  Club members bonsai critique -November 2017

Sheila opened the meeting with congratulations to Jim Kopenhaver who was elected president of SBC for next year. She welcomed Mauro Stemberger back to SBC and gave us an update on Mauro’s activities for the year. Mauro is now sporting a wedding ring and has essentially completed a bonsai book which will be available in the spring.

Mauro began his tree evaluation with his usual grace and visual acuity. The first tree presented was a Limber Pine (Pinus flexilis). Limber pines have short needles and bud back easily. Mauro is not a fan of the windswept style. He suggested looking for the front and developing the style, remove the bark from the existing gin. Mauro saw a smaller tree by creating separate jinn without a shari with the straight branch and then developing an apex by that jinn. Use the more compact part of the tree to develop the branches of the tree. The branches can be reduced slowly. In spring pinch the candles, letting the buds grow until July and then cut shoots by Âľ, buds will form at the base of the cut candle. Wait until the candles harden off and cut off the old candle in the spring.

Privet (Ligustrum sp.) is a strong grower. Mauro suggested building taper to the trunk with 4 to 6 diameter changes since this is a strong tree and a fast grower. The root ball can be reduced, but first finish the tree and then put it into a bonsai pot. After the spring shoots are hardened, you can defoliate the tree and shape it and it will grow again. Build the branches and reduce the length and work on the shape. In the spring, work on the inner lines, wire and create structure of pads and start to shorten the tree. After the tree is developed and in a bonsai pot, control growth and size of leaves by slightly stressing the tree with less water. Food, light and water quantities control growth. We do not want to have a branch take off and destroy the form of the tree. Deciduous trees’ root ball can be cut hard when potting the tree. Conifers’ root ball cannot be cut back drastically when re-potting.

Yew (Taxus baccata): The tree was collected from a tree nursery and was growing in clay soil. The root ball was cleared of the clay soil and planted in “bonsai soil”. Mauro said that this was a fine procedure for a yew since it does not require mycorrhizal fungi in order to grow as pines do. It would be better to be planted in a soil that does not have any organic material in it since the organic material will hold water. The tree needs a good draining and airy soil when the branches are wired and pinched and growth is controlled. Akadama, pumice, and lava in 2-1-1 ratio would be an example of an appropriate soil. It has a good root ball. Next decide where the front is, bring the tree a little forward to increase the concept of three dimensions. Next, start up the trunk and select first, second and back branches. The lower back branch could be moved forward to become a welcome branch. Remove the chicken feet roots and decide which of the two uprights will become the apex. The other top branch could be a back branch or possible a jinn. When we start shaping, we want the tree’s energy to go to the branches rather than to the apex.

Pitch Pine (Pinus rigida): Treat like a black pine. Change the angle of the tree, it can reach this angle. This will bring some roots above the soil line. The exposed roots will need to be potted as the nebari is adjusted to soil level. Hide the bend in the back and bring the branches forward. Push the bottom branch down and shorten some of the lines. Subdivide the pads to develop them. Move the rhythm up the tree, from heavy strength of the bottom to lighter on the top. Reshape the back dead branch to a hollow or create a jinn. Bend branches in the cooler weather. Use raffia for large bends and guy wires to bring the branches down and ever few weeks, tighten the wires. Don’t allow the tree to freeze, if you are making adjustments during the winter months rather keep the tree in a cool greenhouse. Avoid the hottest months of the year to do heavy bending.

Boxwood (Buxus sempervirens): Slowly open up the branches which are now too close. If the tree has room it will fill the space. Develop back branches to create depth. Prune harder on top to develop branches. If the pads are nice, allow it to grow a couple of inches and then prune and continue to clip and grow.

Rocky Mountain Juniper (Juniperus scopulorum): Check what is under the soil for the nebari – where is the original root ball? First build your plan – what is your design, and then take away everything that is not necessary, then clean and wire the entire tree. Junipers respond to being wired, twisted and breaking the fiber of the wood, it will recover more quickly than if the fibers are not stressed. That is the first step of your journey with the tree, there may be more than one option that is pursued during the journey with the tree. Junipers require as much sunlight as they can get. Grow in full sun to get strong compact trees. Yews, on the other hand, are an under-story tree and grow well with reflected light. If the tree is not used to growing in direct sunlight, slowly move it into more intense light to prevent the leaves from burning.

Yew (Taxus sp.): This specimen was grown in the ground and collected then fed heavily. The top was killed off and a jinn formed. Reduce the jinn since it is overpowering the tree. Build the proportions for the tree. Possibly open up a shari to define the edges of the live vein. Possibly change the orientation and have the right branch be the apex. We do not have to limit our imagination to the angle the tree was potted. Use all the information you can get from the tree, sometimes the hidden idea is the better one. An exception to this is Mugho Pine which will grow more strongly if it does not have to reorient itself.

To see more of Mauro’s handiwork or to reserve his book, go to his website at