Blowing away the arguments against big trees in Bangkok
Concerns over branches falling onto power cables during storms and causing blackouts, or that the city's streets are not wide enough to accommodate large species that could brighten up the Big Mango simply don't hold water
Last week's column on Pterocarpus indicus, or pradoo, in bloom on Rama IV Road made me pay closer attention to trees along Bangkok's streets. Five days a week I have to fetch my grandson from school in the Dusit area, and from my gate near Suan Phlu to the school, I pass by many trees along the way.
PRETTY IN PINK: Flowering ‘Lagerstroemia speciosa’ on Rama IV Road.
From days of observation I have concluded that there's no reason why most of our street trees are not allowed to grow to their fullest apart from the unreasonable fear that branches might break and fall on motorists, and probably the desire to make them neat.
TOWERING TREASURES: ‘Pterocarpus indicus’, or ‘pradoo’, provide shade for motorists on Banthad Thong off Rama IV Road.
Some might say that Bangkok is festooned by electric wires and cables that could be brought down by branches during a storm. Others might contend that the streets of the city are too narrow to accommodate big trees. I beg to differ with both points of view.
During a visit to Taiwan years ago, a typhoon was expected to hit Taipei the night I arrived. Having grown up in a country battered by an average of 24 typhoons a year, the news did not frighten me; on the contrary it excited me - for the first time in decades I was about to experience a typhoon once again. The Grand Hotel where I was staying was on a hilltop and had a commanding view of the city, and from my ninth-floor room I watched with anticipation as it began to rain.
As the storm gathered momentum I soon realised that Taipei was directly in Typhoon Nelson's path. The howling winds at 173kph and the blinding sheet of rain brought back memories.
But although I grew up with typhoons, my hometown in Central Luzon in the Philippines was seldom in the centre of a storm and I had never observed a typhoon from such a vantage point. Standing on the patio of my room, watching cars being swayed by the winds in the car park, I was awed by what Mother Nature could do, but was shaken when the onslaught of the gale-force winds nearly swept me off my feet and a lighting fixture from the patio of the room next to mine flew over my head.
A LONG WAY TO GROW: ‘Alstonia scholaris’, or ‘phya sattabahn’ on Ratchadamri Road. These trees can reach a height of 40m.
Typhoons such as this uproot trees and snap branches, but Bangkok has rarely, if ever, been hit by such a storm. By pruning away branches likely to interfere with power cables, the risk of the branches causing a blackout is minimised.
As the trees grow, the branches become higher than the cables, and the risk of branches coming into contact with them is eliminated.
Several pradoo had escaped the axe-wielders on Banthad Thong off Rama IV Road and, higher than the roof of a nearby row of three-storey shophouses, the grand trees are a sight to behold.
The other argument, that Bangkok is not designed for big trees as the streets are too narrow, doesn't hold up either. Our own soi is just wide enough for two cars to meet, but it is shaded in parts by trees on either side of the road. The trees, mostly pink tabebuia (Tabebuia rosea, or chompoo panthip) and flame trees (Delonix regia), are in private compounds and although the owners hardly trim them, I have never seen branches snapping and hitting passing cars. However, privately owned trees need pruning, too, to remove weak and dead branches. The Metropolitan Electricity Authority has a unit whose job is to prune branches too close to power cables, and in their free time some of the workers trim trees on private land for a fee.
HISTORIC HORTICULTURE: Tamarind trees on Ratchadamnoen Avenue and outside Chitralada Palace were planted during King Rama V’s reign. PHOTOS: NORMITA THONGTHAM
Pink tabebuia and flame trees are very attractive when they shed their leaves and replace these with bright pink and crimson flowers, but where hardiness, shade and beauty of form are concerned they cannot beat the pradoo with their shiny leaves and willowy branches that sweep downwards. However, while pradoo are small their lower branches must be removed to get these out of the way of pedestrians or motorists.
Trees which do not require much trimming are those in the Lagerstroemia family that include inthanin-nam (Lagerstroemia speciosa, also known as L flor-reginae, queen's crape myrtle or pride of India), tabaek, or tabaek-na (Lagerstroemia floribunda), and salao plueak bang (Lagerstroemia venusta). The medium-sized trees grace many streets of Bangkok with their attractive mauve-purple or pinkish flowers that remain on the tree for several days during summer and turn almost white before they fall.
All the above are young compared to the grand old tamarind trees along Ratchadamnoen Avenue and the Dusit area outside Chitralada Palace, which were planted during the reign of King Rama V from the late 19th to the early 20th century. But these have a neat trim look and have not been allowed to grow as tall nor as sprawling as they should. New on the scene are the mahogany trees in the middle of Rama IV Road and the "devil trees" (Alstonia scholaris, known in Thai as sattabahn or phya sattabahn) along Ratchadamri Road. If all the trees on Bangkok's streets were placed side by side, the sattabahn with their straight trunks and layered crowns could easily tower over most of them; they can grow to a height of 40m.
There's a Chinese proverb which says, "The best time to plant trees was 20 years ago. The next best time is now." Whether along streets or in private compounds, trees planted now will benefit future generations 20 years later. That's the length of time needed before timber can be harvested, but that's another story.
About the author
- Writer: Normita Thongtham