Ferocactus emoryi is one of the most common and, at the same time, most beautiful cacti in the world. Its long, sharp spines of a beautiful red color attract all eyes, I would even dare to say that not all those eyes that observe it are from cactus-lovers. 
Although it is not a plant that we could label as "harmless", it is true that it is one that is taken care of quite easily. In fact, this cactus is suitable for beginners, with this I say it all. Well, everything… everything… no. You can read the rest below.
How is it?
Image from Desertmuseum.org
Ferocactus emoryi It is a cactus native to Arizona (United States) and Sonora, Sinaloa and Baja California Sur (Mexico). It was described by George Engelmanny Charles Russell Orcutt and published in Cactography in 1926.
It is a plant with a single spherical or cylindrical stem of light green to glaucous color up to 2,5 meters high by 1 meter in diameter.. It has 15 to 30 ribs with areolae, from which the white to reddish spines arise. The central spine is flattened, straight, curved and measures 4 to 10cm long, and the seven-nine radial ones are up to 6cm long. The flowers are large, up to 7cm in diameter, and can be red, yellow, red, or red with yellow. The fruit is ovoid and is 5cm long.
There are three varieties:
- Ferocactus emoryi subsp. emoryi
- Ferocactus emoryi subsp. covillei
- Ferocactus emoryi subsp. rectispinus
What are their cares?
To take care of this cactus correctly it will be enough with place it in a sunny exposure, with substrate or soil that has very good drainage, and water it very little. In this sense, we must always bear in mind that it does not tolerate waterlogging: it is better to water once a week than 3 or 4, even if it is very hot, since otherwise we would lose it.
Also, it is convenient to go transplanting it in spring every 2-3 years, and transfer it to the garden as soon as it becomes dangerous to remove it from the pot.
Resists cold and frost down to -4ºC.