Aloe thraskii is an unbranched tree-like succulent, up to 10 feet (3 m) tall, with deeply concave (U-shaped in cross section) pale olive-green leaves that have small reddish-brown marginal teeth and are recurved back to the trunk, sometimes even touching the skirt of old, dried leaves around the trunk. This winter-blooming species has flowers on a well-branched inflorescence that can produce 15 to 25 upright broadly-cylindrical erect racemes with yellow flowers that have orange anthers, giving the flower a bicolored look. Younger plants may only produce a single inflorescences while older ones can produce multiples. Aloe thraskii is closely related to Aloe excelsa and Aloe rupestris but is distinguished from both by its strongly recurved leaves.
Light: Strong, bright light. They can withstand full summer sun, once acclimated. In the winter, provide bright light. Water: Water generously in the summer and nearly cease watering in the winter. Do not let water stand in the rosettes. Temperature: Prefers warmer temperatures of 70ºF/21ºC to 80ºF/27ºC, but will survive down to 40ºF/4.5ºC. Soil: A well-drained potting mix is essential; use a cacti or succulent mix. Fertilizer: Feed with a cactus fertilizer in the summer only. Suspend feeding in the winter as the plant goes dormant.