Indoor cacti are striking, low-maintenance plants that thrive on bright light and infrequent watering, making them perfect for sunny windowsills. Place your cactus where it can receive at least six hours of bright, direct to bright indirect light—a south or east-facing window is ideal. Use a fast-draining cactus/succulent soil mix in a pot with drainage holes, and water only when the soil is completely dry to the bottom; typically every few weeks. During spring and summer, water thoroughly but allow the pot to drain completely—then significantly reduce watering in winter as the plant rests. Keep humidity low and avoid misting, as excess moisture can lead to rot. A light feeding in the growing season and repotting only when the plant truly outgrows its container will keep your cactus happy and thriving.