E. melanostele is a slow growing columnar cactus which grows up to 7 feet (2.1 m) tall, but raised in a pot it will reach up to 10 inches (25 cm) in 10 years. Even at a very young age, the cactus displays an abundance of long, woolly spines that cover and hide the body of the plant including sharp, white, yellow or red spines up to 1.5 inches (3.8 cm) long.
Flowers are rarely born on a cephalium, unlike its close cousin E. lanata. When it blooms, it has orchid-like white flowers.
Originating from the hilly regions, this species requires low maintenance and enough sunlight to grow. This needs a little more water than most cacti for a healthy growth.
If kept outside it requires full sunlight and a bright spot if kept inside. During the growing season fertilising and watering regularly is the key to best results.
It is an excellent plant for garden rockery settings, desert type landscapes, patios and botanical gardens
For watering cacti, the golden rule is to make sure the soil is completely dry before watering! This will stop the roots from rotting. It is advised to always use a pot with a drainage hole so that excess water can get drained out. If kept in a sunny area, you will need to water it once every week. If it is in a semi shaded or filtered light area, you might need to water it once in 2 weeks.
Cacti like soil that is well aerated and fast draining. You can fertilise the cactus in the summer months when it is in its growing season. During the winters it is best to cut back on any fertiliser and let the plant rest.