SKY-HIGH

Navarat Komutanont has grown a tree for 36 years. It has become so tall that her closest neighbours are concerned about it. Now she is in a dilemma: Should she cut down her beloved tree to satisfy the neighbours, or should she preserve it?

TOO TALL: Navarat Komutanont’s ‘Araucaria’ tree. Her neighbours are concerned that it might fall or the trunk could break.

"I have grown the tree since it was only about two feet [60cm] high," she writes. "We never thought that it would grow so sky-high."

She believes it to be Araucaria columnaris, or Cook pine, as it displays the species' two distinctive characteristics - a curvature in its trunk, and flaky bark. "Its flakiness is quite pronounced all over the entire trunk, but I have yet to see the tree produce its 'pollen cone' flowers," she writes. "I wish to maintain and preserve my pine tree, which looks quite healthy with an aerodynamic shape. It is twice the height of a two-storey house, so I am quite keen to find the best way to support it in order to relieve some of the neighbours' concerns that the tree would fall or the trunk would break.

"Their anxieties are probably due to the frequency of unusually strong winds lately and the tree's extraordinary height. It would be heart-breaking if the tree is cut down, or even if its height is reduced to half, as it would lose its shape.

"I would appreciate it if you could guide me to a professional arborist who could perform inspections to see whether it is as stable and as healthy as it appears. Should it become necessary to mechanically support the trunk with cables or some kind of logical support, is there someone able to calculate an accurate mathematical formula for an environment-friendly support and construct it?"

A tree native to the Cook Islands, in the South Pacific northeast of New Zealand, the Cook pine is often mistaken for the Norfolk Island pine (Araucaria heterophylla), known in Thai as son chat. As Ms Navarat knows only too well, the Cook pine's trunk has the tendency to have a slight curve. Despite its name, columnaris, its trunk is never straight. The Norfolk pine, on the other hand, always has a straight trunk.

Another distinctive characteristic is its flaky bark. Unlike the Norfolk pine, the bark of the Cook pine peels off in paper-thin strips. The latter bears flower-like pollen cones that grow on the ends of the leaf-branchlets near the top of the tree, which is probably the reason why Ms Navarat has never seen them - her tree is simply too high for her to see the cones. Either that, or Bangkok's climate may not be cold enough to induce flowering.

MISTAKEN IDENTITY: When small, the Cook pine is often mistaken for the Norfolk Island pine (above).

In both Cook and Norfolk pines, the leaves of juvenile trees look markedly different from those of mature trees. The leaves of the two species are almost identical, but the branches of the Cook pine tend to grow closer together while the Norfolk has much more space between the layers of branches. Also the branches of the Cook pine droop down more than those of the Norfolk, and they tend to break off closer to the main trunk and then grow numerous short secondary branches, giving mature trees a narrow, conical appearance with column-like trunks.

Both the Cook and the Norfolk pines tolerate a wide range of soil and in favourable conditions grow up to 60 metres tall. As coniferous plants they have their own particular form so it is best to allow them to grow naturally. The only pruning they need is to remove dead branches.

We have three Cook pines and five Norfolk pines on our farm but they are still small. The Cooks were planted four years ago and are now two to three metres high, while the Norfolks were planted only last year and the tallest is still only about a metre high. Therefore I don't have the experience needed to advise Ms Navarat on what to do with her tree.

If there are any readers out there who have faced the same dilemma or who could answer Ms Navarat's questions, please contact this column.

Meanwhile, Rungnapha Leedy wants to know whether there are garden and landscape designers who live in the Udon Thani area. She has seven rai and would like professional help with the designs. If you can help, please send your contact address to this column so Mrs Leedy can get in touch with you.

Post your questions on the readers' forum at http://www.thaigreenfingers.com or email normita@thaigreenfingers.com.

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