Conophytum subfenestratum is easy to grow. These plants grow on winter rain and head for summer dormancy. More or less dormant in summer. The plant requires little water; otherwise its epidermis breaks (resulting in unsightly scars). Water throughout the year although minimally in summer, (only when the plant starts shrivelling), but it will generally grow even in summer if given water. Water regularly in winter after the previous year's leaves have dried up. Requires good drainage. Keep cool and shaded from hot sun in mid-summer; it needs full sun or light shade in the other seasons. Hardy to -2°C. Ensure a very good ventilation. Avoid to repot frequently. This plant may stay in the same pot for many years. Plants grown in larger containers have frequently relatively poor flowers. It might improve when the plants are given their own, small individual pots.