Wisteria Bonsai by David Johnson May 14, 2001 See a large image of this tree Flowering and fruiting bonsai can add a lot to anyone's bonsai collection. The beauty of flowers and fruit illustrate the possibilities of presenting bonsai in a different way to both the experienced bonsai hobbyist and the general public. For newer plant material, one can receive more immediate satisfaction by enjoying the flowers and fruit which attract the attention of the viewer while the tree is still undergoing the necessary long term process of developing good surface roots, old bark, branch ramification, the tree's overall shape etc. Wisteria are an excellent example of flowering bonsai. Wisteria is a deciduous climber with long racemes of scented white, pink, blue or mauve pea-flowers. The flowers normally bloom in May and June. The leaves open sometimes during but mostly after the height of flowering. The leaves are pinnate having the leaflets arranged on either side of a central stalk. Like most flowering bonsai, the flowering season is the time to display the tree. The foliage that comes after may not be that attractive but is necessary to produce flowers for the following year. The two species of wisteria commonly used for bonsai are Chinese wisteria (Wisteria sinensis) and Japanese wisteria (Wisteria floribunda). April 2001 I have a wisteria that I brought to the May 2001 Toronto Bonsai Society meeting. This wisteria was another great tree given to me by Calvin Chong before he returned home to Jamaica. I acquired the tree in August 1997. However, Calvin had done a lot of work and training on the tree before it came into my care. I e-mailed Calvin to ask about the tree's earlier history and, like all good bonsai artists, he sent me back a detailed record. Calvin's record: Japanese wisteria - wisteria floribunda 1992 (spring): Purchased tree at Clargreen Garden centre. The tree had a 1/4 inch trunk. 1993 (spring): Planted in ground, pruned into single tree form and trained up dead maple 1994: Pruned regularly during the growing season. The branches were left to grow 4 to 5 feet long and then cutback to 2 or 3 buds. 1995 (spring): The tree flowered for the first time (2 or 3 flowers). Pruned in same manner as previous year. 1996 (spring): The tree flowered with more flowers and produced pods. Pruned as previous year. 1997 (early spring): The tree was dug from the ground, root pruned and planted in a large balcony container. The tree flowered quite a lot. (summer): The tree roots were washed, pruned, arranged and potted in an azalea pot. Pruned as previous year. Some of the remarkable points in Calvin's report is his success in increasing trunk size from 1/4 to 2-1/4 inches, measured at 6 inches above the existing 6-inch diameter base. The bulk of this growth occurred under Calvin's care with the planting of the tree in the ground and heavy pruning throughout the growing season. Calvin was also fortunate to have a tree that flowered after only three years. Spring 1999 After acquiring the tree, I spent some time deciding how to style it. In spring 1999, I repotted the tree in the same pot but centred it more with a trunk lean to the left. This was difficult because the roots were tightly bound and filled the pot (some of the Japanese literature suggests this condition helps to promote flowering). The next spring (2000), I heavily pruned about 50% of the foliage and wired the main branch. October that year I repotted the tree in a blue Korean container to compliment the purple flowers. I pruned off 60% of the foliage and 10% of the roots. I adjusted the tree's angle and continued with my efforts to centre it. In May 2001 when the tree was on display, I noticed that its canopy of flowers obscured the trunk's movement to the left. The trunk seemed to grow straight up instead of the angle it appeared to have before the tree had flowered. The tree had to be repotted at a sharper angle in the future. As I had mentioned earlier, I was constantly trying to centre the tree in its round container. At the end of May 2001, I repotted the tree after the flowers were finished. I pruned 15% of the roots and removed a heavy branch on the right side of the tree in order to emphasize the tree's movement to the left. Unfortunately, wisteria take some time to heal over large cuts. The tree was repotted at a sharper angle to the left. Roots on the right that were exposed by this angle change were gradually pruned back and exposed. Another problem was the absence of roots on the left side of the tree which made it look unbalanced. During the summer of 2001, two sucker shoots appeared in this area. After the shoots grew to about 3 inches I gradually bent them down toward the soil. Then I cut the ends, applied rooting hormone and shoved them into the soil, hoping they would root. So far it looks like it is working. Suckers have appeared at other locations along the trunk but I removed the ones that did not fit the design. May 29, 2001 I also pruned excessive foliage (tendrils and foliage extensions that were too long for the overall design) and upward growing leaves to allow for more light and flower bud development. I used the International Bonsai, 1990 #1 issue devoted to wisteria as a source for this tip and other ideas. Most of the literature translated from Japan suggests that the wisteria's container should sit in a basin of water because the tree loves water, especially during the hot summer. It is said to encourage flowering but one article suggests that the tree be kept on the dry side to serve the same end. I must have read the water basin article first or else Calvin told me to do it because I am using the water basin method with success. I feed the tree heavily after flowering with a variety of fertilizers that emphasize phosphorous and potassium. I use Japanese fertilizer cakes, Bateman's organic "Bounty" (6-2-2) and "Sturdy" (0-15-14) and Wilson's "Fish Based Flowering Plant Food 5-10-5." In the fall 2001, I acquired some new organic fertilizers by Organic, "Raingrow 4-2-3" and "Bloom-A-Long 0-12-0" that I plan to use in the coming year, 2002. June 1999 White Rose has a hand-out with recommendations for garden growing wisteria that might be valuable for bonsai culture. They suggest that high-nitrogen fertilizer will promote excessive stem and foliage growth at the expense of flower bud formation. Instead, they recommend a low-nitrogen fertilizer such as "Iron Plus 4-8-12." According to the hand-out: "Root pruning may also be carried out by forcing a sharp spade into the soil in a circle around the plant, thus cutting all the side roots. This procedure will not harm the plant but makes the plant think it is going to die and in order for it to preserve itself will be forced into bloom." This suggestion could allow for heavy root pruning in bonsai culture. Here are some references readers may use if you want to grow a wisteria: International Bonsai, 1990 #1 Bonsai Today, #38, #52, #71 Bonsai Magazine (Bonsai Clubs International), 1993 #1, #2, #3, #4, 1994 M/J