Opuntia microdasys, commonly known as bunny ear cactus or polka dot cactus, is a charming and distinctive cactus species valued for its symmetrical pads and unique clusters of soft-looking spines. This Opuntia species features flattened, oval-shaped green pads that appear in pairs, resembling bunny ears. Instead of sharp spines, it is covered in numerous clusters of small, hair-like, yellowish or reddish-brown barbs called glochids. Its whimsical appearance makes it a popular choice for indoor plant collections in the UK. It is a member of the Cactaceae family.
The genus name Opuntia is derived from Opous, an ancient Greek city. Microdasys comes from Greek words meaning "small and hairy," referring to the tiny clusters of glochids.
Light: Opuntia microdasys thrives in full sun. It requires at least six hours of direct sunlight daily to encourage robust growth and prevent the pads from becoming leggy. When growing indoors in the UK, placing it in the brightest available window is crucial.
Water: Water sparingly. This succulent cactus stores water efficiently in its pads, so allowing the potting mix to dry out completely between waterings is vital. During the active growing season (spring and summer), water thoroughly, ensuring all excess moisture drains away. Significantly reduce watering in autumn and winter when the plant is dormant. Overwatering is a frequent cause of rot.
Soil: A very well-draining potting mix is essential. A specialist cactus or succulent mix is ideal. This type of mix will help prevent water accumulation, which is crucial for the plant's health, particularly in the UK's often damp climate.
Fertilising: This plant is not a heavy feeder. During the growing season (spring and summer), a diluted liquid fertiliser formulated for cacti and succulents can be applied monthly. Reduce or stop fertilising during the dormant period.
Temperature: Opuntia microdasys prefers warm temperatures and is not reliably frost-tolerant. It thrives in warm, dry conditions and should be protected from temperatures below 10°C (50°F). If grown outdoors in the UK, it should be brought indoors before temperatures drop in autumn.
Humidity: Average household humidity levels are sufficient. This plant prefers dry air and does not require high humidity.
Growth Habit: It typically grows as a bushy, upright cactus, forming a cluster of flattened, paddle-shaped segments. It remains a relatively manageable size when grown in containers.
Toxicity: While Opuntia microdasys is generally considered non-toxic to humans and pets in terms of chemical compounds, its fine, barbed hairs (glochids) are a significant physical hazard. These glochids detach easily and can cause severe irritation, itching, and inflammation if they get into the skin, eyes, or are ingested. Always wear thick gloves and exercise extreme care when handling this plant, and keep it in a safe location away from children and pets to prevent physical injury.