Theory:

SECTION - I
     One morning while I was sitting beside Grandfather on the veranda steps, I noticed the tendril of a creeping vine trailing nearby. As we sat there in the soft sunshine of a North Indian winter, I saw the tendril moving slowly towards Grandfather. Twenty minutes later, it had crossed the step and was touching his feet.
 
     There is probably a scientific explanation for the plant’s behaviour - something to do with light and warmth perhaps - but I liked to think it moved across the steps simply because it wanted to be near Grandfather. One always felt like drawing close to him. Sometimes when I sat by myself beneath a tree, I would feel rather lonely but as soon as Grandfather joined me, the garden became a happy place. Grandfather had served many years in the Indian Forest Service and it was natural that he should know trees and like them. On his retirement, he built a bungalow on the outskirts of Dehradun, planting trees all around - lime, mango, orange and guava, also eucalyptus, jacaranda, and Persian lilacs. In the fertile Doon Valley, plants and trees grew tall and strong.
 
     There were other trees in the compound before the house was built, including an old peepul that had forced its way through the walls of an abandoned outhouse, knocking the bricks down with its vigorous growth. Peepul trees are great show offs. Even when there is no breeze, their broad-chested, slim-waisted leaves will spin like tops determined to attract your attention and invite you into the shade. Grandmother had wanted the peepul tree cut down but Grandfather had said, ‘Let it be, we can always build another outhouse.’
 
     Grandmother didn’t mind trees, but she preferred growing flowers and was constantly ordering catalogues and seeds. Grandfather helped her out with the gardening not because he was crazy about flower gardens but because he liked watching butterflies and ‘There’s only one way to attract butterflies,’ he said, ‘and that is to grow flowers for them.’
SECTION - II
     Grandfather wasn’t content with growing trees in our compound. During the rains, he would walk into the jungle beyond the river-bed armed with cuttings and saplings which he would plant in the forest.
 
     ‘But no one ever comes here!’ I had protested, the first time we did this. ‘Who’s going to see them?’
 
      ‘See, we’re not planting them simply to improve the view,’ replied Grandfather. ‘We’re planting them for the forest and for the animals and birds who live here and need more food and shelter.’
 
      ‘Of course, men need trees too,’ he added, ‘To keep the desert away, to attract rain, to prevent the banks of rivers from being washed away, for fruit and flowers, leaf and seed. Yes, for timber too. But men are cutting down trees without replacing them and if we don’t plant a few trees ourselves, a time will come when the world will be one great desert.’
 
     The thought of a world without trees became a sort of nightmare to me and I helped Grandfather in his tree-planting with greater enthusiasm. And while we went about our work, he taught me a poem by George Morris:
 
Woodman, spare that tree!
Touch not a single bough!
In youth it sheltered me,
And I’ll protect it now.
 
     ‘One day the trees will move again,’ said Grandfather. 'They’ve been standing still for thousands of years but there was a time when they could walk about like people. Then along came an interfering busybody who cast a spell over them, rooting them to one place. But they’re always trying to move. See how they reach out with their arms! And some of them, like the banyan tree with its travelling aerial roots, manage to get quite far.’
 
     We found an island, a small rocky island in a dry river-bed. It was one of those river-beds so common in the foothills, which are completely dry in summer but flooded during the monsoon rains. A small mango tree was growing on the island. ‘If a small tree can grow here.’ said Grandfather, ‘so can others.’ As soon as the rains set in and while rivers could still be crossed, we set out with a number of tamarind, laburnum, and coral tree saplings and cuttings and spent the day planting them on the island.
SECTION - III
     The monsoon season was the time for rambling about. At every turn, there was something new to see. Out of the earth and rock and leafless boughs, the magic touch of the rains had brought life and greenness. You could see the broad-leaved vines growing. Plants sprang up in the most unlikely of places. A peepul would take root in the ceiling; a mango would sprout on the window-sill. We did not like to remove them but they had to go if the house was to be kept from falling down.
 
     ‘If you want to live in a tree, that’s all right by me,’ said Grandmother crossly. ‘But I like having a roof over my head and I’m not going to have my roof brought down by the jungle.’
 
     Then came the Second World War and I was sent away to a boarding school. During the holidays, I went to live with my father in Delhi. Meanwhile my grandparents sold the house and went to England. Two or three years later, I too went to England and was away from India for several years.
 
     Some years later, I returned to Dehradun. After first visiting the old house – it hadn’t changed much – I walked out of town towards the river-bed. It was February. As I looked across the dry water-course, my eye was immediately caught by the spectacular red blooms of the coral blossom. In contrast with the dry river-bed, the island was a small green paradise. When I went up to the trees, I noticed that some squirrels were living in them and a koel, a crow pheasant, challenged me with a mellow ‘who-are-you, who-are-you.’
 
     But the trees seemed to know me; they whispered among themselves and beckoned me nearer. And looking around I noticed that other smaller trees, wild plants and grasses had sprung up under their protection. Yes, the trees we had planted long ago had multiplied. They were walking again. In one small corner of the world, Grandfather’s dream had come true.
 - Ruskin Bond
Reference:
State Council of Educational Research and Training (2019). Term-1 English Standard-6. When the Trees Walked - Ruskin Bond (pp. 107-122). Published by the Tamil Nadu Textbook and Educational Services Corporation.