Once again the Japan Society came up trumps with a great trip to Kew Gardens to learn about bonsai. And again I have to make a confession – though I’ve been to Kew a lot and was sure I’d seen all the Japanese stuff there (Chokushi Mon, Minka House, Japanese Landscape Garden – done!) I’ve never been to look at the bonsai.
I do have an excuse – they’re in a little glasshouse tucked away in a corner of the gardens. If you’re planning to go, head towards the Princess of Wales Conservatory, and you’ll find the bonsai house between the Davies Alpine House and the student vegetable plots.
The bonsai collection at Kew began with a donation by Ruth Stafford-Jones who, over a period of thirty-seven years, built up the finest bonsai collection in Europe. They’re very valuable so don’t touch – you might set off the alarms!
Kew has nearly sixty trees now, the oldest being 180 years old. This chinese quince from Nagoya is around 130 years old. (The wood from full-sized trees is used to make musical instruments):
This Hall crab apple is around fifty years old. Although bonsai trees are tiny, their flowers and fruit are full-sized.
The most common bonsai trees are maples and pines.
The advantage of going with the Japan Society was that, not only did we get breakfast in the Orangery, we were also shown round by Richard Kernick, the Kew Gardener who looks after the bonsai, and saw the private area where he works and keeps many more plants than are on public display.
I was pretty ignorant about bonsai before this trip. I knew they were real trees, kept small by constant pruning. But I didn’t realise that just taking them out of the pot and chopping off a few roots occasionally wouldn’t be enough. Richard explained that the pruning was designed to remove thick roots that took more energy to maintain than the nutrients they absorbed provided (though he kept thick roots on the surface for aesthetic effect) and also long roots that curled round the pot. The aim was fine roots with lots of filaments to get plenty of nutrition to the plant.
Richard showed us the fertilisers he used – most imported from Japan and far from cheap, though he gets pumice in the UK. The main imported one is Acadama (red ball) which he sieves out into three groups; large, medium and fine grain which is used for seedlings and cuttings.
Bonsai trees are ordinary trees that have been deliberately kept small – if you plant bonsai trees out and give them room to grow, they will turn back into normal size trees. They need plenty of water – Richard soaks the pot to drive out air the roots have exhausted and allow fresh air to be drawn into the pot. Bonsai need to be re-potted every few years to give them fresh soil to replace the minerals and nutrients they’ve used up. And they need pruning regularly otherwise the roots build up and the plant gradually rises out of the pot.
He also showed us good and bad bonsai pots. Good bonsai pots have drainage holes in the corners, so you can tilt the pot and all the water will drain out, and straight sides. Curved sides make it hard to get the tree out for pruning.
The most interesting thing Richard told us was in answer to a question about bonsai styles. He said that in the west people tend to be concerned about pruning their bonsai into certain styles, whereas in Japan they look at the shape of the bonsai and then describe it as being a certain style. ‘In Japan the tree comes first and the style comes after,’ he said. Food for thought.