Theory:

     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.
Explanation:
 
The monsoon season had started. The author says that monsoon was the time for rambling about. It means rambling in two senses. One refers to wandering about. Wherever the author wandered in his city, he saw something new in every turn. The other meaning refers to the plants putting out long shoots and growing over walls or other plants. All the plants had sprung up out of the earth, from leafless branches, fresh and new in the rains during the monsoon.
 
spring s.jpg
The magic touch of rains brought life and greenery!
  
It symbolizes new life and lush green vegetation. The creeping trees with broad leaves in their garden grew up. Plants came out of unexpected places like
  • Peepul tree roots went into the ceiling.
  • A mango plant sprouted in the window sill.
They did not want to remove them, but they had to remove it; otherwise, the house will fall under the weight of the trees. His grandmother said annoyingly that if they wanted to live in a tree, it was alright, but she wanted to have a roof over her head and not want the roof to be collapsed by the jungle. She expressed it sarcastically.
 
It was the time of the Second World War (between \(1939\)-\(1945\)). The author had been a school kid by then, and he was sent away to a boarding school. During his holidays he went to Delhi to stay with his father. His grandparents had sold the house in Dehradun and moved to England. After two-three years, he also went to England and stayed away from India for several years.
 
Meanings of difficult words:
 
No.
Words
Meanings
1
rambling
1. wandering
2. (of a plant) putting out long shoots and growing over walls or other plants 
2
unlikelyimprobable, not likely to happen
3
crosslyannoyed
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.