What is a Thanksgiving Cactus?

The Thanksgiving cactus, or Schlumbergera truncata, is a small tropical plant that can grow up to 12 to 24 inches (about 30.5 to 61 cm) high with thick, flat green leaves and variously colored flowers that range from white to red. The Thanksgiving cactus bears many similarities to the Christmas cactus, with the main differences between the varieties being the time of year the flowers blossom and the shape of the leaves. As its name implies, a Thanksgiving cactus typically blooms in late fall, which is when the Thanksgiving holiday occurs in the U.S., as opposed to the Christmas cactus, which typically blooms in the winter around its namesake holiday. In addition, the leaves of the Thanksgiving variety are more jagged than those of the Christmas variety and are often said to look like crab claws; hence the plant’s alternate name of the crab cactus in areas of the world that do not celebrate Thanksgiving.

Originally from Brazil, Thanksgiving cacti can now be found around the world. Optimal growth and blooming are generally dependent on several factors, including soil, sunlight exposure, and temperatures. The plant is suited to warmer temperatures and is not considered cold hardy in most areas. For this reason, it is often grown as a houseplant or as an indoor or outdoor potted plant, being left outside in the warmer months and brought in during the cooler months.

A Thanksgiving cactus typically requires a specific type of environment to ensure optimal growth and proper flower blossoming. The soil must usually be well drained and kept moderately moist, but not wet. In warmer months, it requires placement in a partially shaded area, while in the cooler months it needs direct sunlight. To develop flower buds, the plant must usually be exposed to evening temperatures of less than 60°F (about 15.6°C) and to no more than 12 hours of sunlight a day. After successful budding, a Thanksgiving cactus will typically blossom about six weeks later. A Thanksgiving cactus’ natural tendency to bloom in the late fall in the northern hemisphere is due to this blooming lead time combined with the fact that the conditions needed for budding typically occur in the period of change between late summer and early fall.