The fairy castle cactus (Acanthocereus tetragonus) is a sun loving plant. The fairy castle cactus grows a number of green branches which resemble a castle, thus getting its name. This plant grows best in the well-drained soils, especially in the clay pots as it easily allows the moisture evaporation. The fairy castle cactus’ maximum growth can be observed in the bright, and sunny locations. This plant is native to North America, Central America and South America and it grows slowly. This plant grows to about 2 meters (6 feet) tall.
Its stems are five-sided and consist of wooly based spines. All stems can grow about 8 inches taller. Areoles are provided with 1-2 spires and they can grow about 1.5 inches. Usually, the color of areoles is yellow or white, and adds additional beauty to the surroundings.
The use of potting mix is an ideal approach to ensure excellent growth; however, gardeners can also prepare good soil mixture by themselves. Mixing of perlite, and sand with one part of the potting mix is the best way to make a gritty medium for fairy castle cactus growth. Only good quality soil should be used to grow this plant. Even if the soil health and quality is not good in a specific region, it can be greatly improved by adding organic matter, compost, and other amendments according to soil type. Soil health is directly related to nutrient uptake by roots, root growth, and penetration, and access to water contents. Poor quality soil directly affects the water and nutrients use of plants, so in this way growth and development are negatively affected. Such kind of problems and growth complications can be greatly avoided by taking care of soil health and quality.
Typically, watering needs of fairy castle cactus are the same as other succulents, and the best growth can be observed by using soak and dry method as in this way, the soil is completely dried in between the watering intervals. Overwatering can cause damage to the growing fairy castle cactus and will exert negative influences on its growth, and development. Moreover, watering should be further reduced during the winter months. Over watering may cause the development of various diseases and fungal attack.
Repotting is the best way to offer good growing conditions, as the roots of these plants need adequate space for growth. So, repotting after a year should be ensured, as in this period the plant usually outgrows its pot. The required amount of fertilizers should also be added in the spring season. However, fertilization application should be done after proper soil testing and determination of plant requirements.
The fairy castle cactus can be easily propagated by using both cuttings and seeds. Even a simple severing of a branch and its replanting in well-drained and moist soil can offer excellent results. Propagation from cuttings can be done by cutting a part of a healthy and vigorously growing stem from the main cactus. The removed stems should be allowed to callous for a few days. Later, the stems can be placed in the well-drained soils. At this stage, complete drying of soil should not be allowed, and frequent but light watering schedule should be ensured.
Other than cuttings, this plant can also be propagated by using good quality and healthy seeds. But the germination from seeds takes a longer time, so this method is not widely used. However, excellent and uniform germination from seeds can be ensured by placing the seeds in the well-drained and nutrient-rich soil. Both indoor and outdoor germination is a good idea, and growers can choose any method according to their interest and growing conditions. Seedlings can also be grown in indoor conditions by providing artificial growing conditions, such as light, temperature, humidity, aeration, and irrigation.