This summer was extremely hot. The lingering summer heat is intense even in September. But the autumn comes to the bonsai world. The season is active time for bonsai care of fertilization, disinfect, picking out the old needles, transplant of Zoki (deciduous trees), and crossbreeding. We interviewed Kiyoshi Hiramatsu, Seijuen bonsai garden in Takamatsu’s Kokubunji town, about the care in this season.

Careful of Fertilization

Bonsai will be active in the autumn and needs to fertilize. Fertilization will help to grow from April to June, and to prepare for getting through the winter from September to November.

There are two types of fertilizer: solid mature and liquid chemical fertilizer. The former will produce an effect slowly on the soil by watering. The latter can serve as watering. The effect is fast and short. So it can be used repeatedly with careful attention to the frequency.

“The key is to feed fertilizer frequently. Over fertilization sometimes causes damage to trees.” Hiramatsu puts a teabag containing an oil cake on the soil. The way is free of influence of watering and makes a long term effect.

Cutting old needles and cross-fertilization of Zoki

Old needles will grow in September if the pine tree has not been trimmed the buds. So the growers cut every old needle they find. It is not easy work to pick them out one by one with hands and tweezers.

It is the best time to transplant Zoki such as Japanese quince, Chojubai quince, Firethorn, and Japanese winterberry. Transplantation should be judged by the solidity of soil and the drain. Some people do for exhibitions in the autumn.

The period from August to September is the cross-fertilization season of the trees with fruits. Hiramatsu showed us the Kadsura japonica’s one. He crossed a refrigerated red male with female of a tree. Then some red beautiful fruits will grow in the autumn.

(By Shigeo Hano)