Bougainvillea thrives in well-draining, slightly acidic to neutral soil. It prefers sandy or loamy dirt with good aeration. A mix of garden soil, sand, and compost works best, allowing roots to stay healthy and preventing waterlogging. Bougainvillea does not tolerate heavy, clay-rich soil, which retains excess moisture and can lead to root rot. To enhance drainage, you can add perlite or coarse sand. Keeping the soil moderately fertile with occasional feeding ensures vibrant blooms.