Rebutia donaldiana, commonly known as Donald’s Red Crown Cactus or Orange Crown Cactus, is a small cactus. Native to the high-altitude Andean mountains of Bolivia, it is admired for its compact, globular form and vibrant orange to red flowers. Its bumpy green body often has bristly, copper-colored spines. It is popular among succulent enthusiasts due to its striking appearance and straightforward care, suitable for both novice and experienced growers.
Rebutia Donaldiana Care
Light
Light is important for Rebutia donaldiana health and flowering. This cactus thrives in bright, indirect sunlight, ideally four to six hours daily. It tolerates some morning sun, but direct midday sun can scorch it. Indoors, a south or west-facing window provides ample brightness. Insufficient light causes etiolation, making the plant stretch and become leggy.
Watering
Watering is crucial for Rebutia donaldiana. These cacti prefer a “soak and dry” method. Water deeply until water drains, then allow the soil to dry completely before rewatering. During the spring and summer growing season, this means watering every one to two weeks, depending on conditions. During fall and winter dormancy, reduce watering to once every four to six weeks. Overwatering causes root rot, as consistently wet soil is detrimental.
Soil and Potting
Proper soil and pot type are crucial for Rebutia donaldiana drainage. A specialized cactus and succulent potting mix with excellent drainage is recommended. The mix should be 70% to 80% mineral grit (coarse sand, pumice, or perlite) with some organic material. Terracotta pots are preferred over plastic or glazed containers due to their porous nature, which allows for better air circulation and faster soil drying. Repot every two to three years, or when rootbound, to refresh soil and provide space.
Temperature and Humidity
Rebutia donaldiana prefers moderate temperatures, ideally 60-85°F (15-29°C) during its growing season. It tolerates cooler temperatures down to 20-25°F (-6 to -4°C), but bring it indoors if frost is expected. During winter dormancy, a cooler environment, around 40-50°F (4-10°C), encourages more blooming. This cactus thrives in low humidity, typically 40-50%. Avoid high humidity, especially in enclosed spaces, as it can cause stress.
Fertilizing
Rebutia donaldiana can grow without frequent fertilization, but nutrients encourage vigorous growth and flowering. During the spring and summer growing season, apply a balanced liquid cactus fertilizer three to four times. Dilute fertilizer to half strength, as cacti are not heavy feeders and can suffer nutrient burn. Suspend fertilizing during fall and winter dormancy.
Propagating Rebutia Donaldiana
Offsets
Rebutia donaldiana is readily propagated through offsets, also known as “pups,” which form around the base of the parent plant. This is the simplest and most successful method for home growers, creating new plants identical to the parent. To propagate, gently twist or carefully cut a pup from the main plant, ensuring a clean separation. After removal, allow the cut end to “callous” or dry for several days to a week. This prevents rot when planted. Once calloused, plant the offset in a well-draining cactus mix. Keep the soil slightly moist until roots establish, typically in four to six weeks.
Seeds
Seed propagation is slower and requires more controlled conditions. Sow seeds on the surface of a sandy, well-draining soil mix, as they require light. Maintain consistent temperature (55-70°F / 16-22°C) and high humidity for germination. Cover the seed tray with plastic wrap to maintain humidity, but ensure periodic ventilation to prevent fungal issues. Seedlings may emerge within two to three weeks, though some take longer.
Common Challenges and Solutions
Root rot is a common issue for Rebutia donaldiana, primarily caused by overwatering or poorly draining soil. Symptoms include a mushy stem, wilting, or yellowing. If suspected, stop watering, unpot, and remove soft, discolored roots. Allow healthy roots and stem to dry and callous for several days before repotting in fresh, dry, well-draining soil with ample drainage.
Pests like mealybugs and spider mites can infest Rebutia donaldiana. These insects cause stunted growth or discolored spines. If detected, treat affected areas with insecticidal soap or neem oil, ensuring thorough coverage. Shriveling or a soft, non-mushy stem indicates underwatering or dehydration. A thorough, careful watering can help the plant rehydrate and recover. Yellowing spines or stunted growth may signal nutrient deficiency, addressed by appropriate fertilization during the growing season.