The best time to plant bougainvillea in India is during the Spring season. this is the time when it grows most rapidly. The second-best time will be just before the arrival of summer. Don’t plant bougainvillea close to winter season, because it needs a fully grown root system to handle the cold weather.The best time to plant bougainvillea in India is during the Spring season. this is the time when it grows most rapidly. The second-best time will be just before the arrival of summer. Don’t plant bougainvillea close to winter season, because it needs a fully grown root system to handle the cold weather.