Old Man of the Andes/Oreocereus Trolli

There are not many longhaired, woolly, tall-growing cacti to choose from, but all are beautiful, becoming more so with age. Most examples of this type of plant are called ‘Old Man’ cacti, and this particular species comes from the Andes.

Oreocereus trollii is very slow-growing and will take perhaps 20 years to reach a height of 60cm (2ft). This cactus is armed with long, fierce, red spines, the whole plant being cocooned in long, white, woolly spines rather like cotton wool in appearance. The plant grows high up in the Andes, the white spines acting as a sun shade in Summer and protection against the cold in Winter. Many species of Oreocereus will eventually become branched clumps about 1.5-3m (5-10ft) tall.

Oreocereus need to be large specimens to flower: thus, they are collected for their beautiful appearance rather than their flowers. Old Man Of The Andes is a choice plant and worthy of inclusion in any cactus collection. This plant is easy to grow and tolerant of low temperatures (to 10°C/50°F) if kept fairly dry. Like most plants, it will benefit from good ventilation, but not draughts.

Provide this plant with bright light at all times; it will grow happily in a South-facing window.

Water well during the Summer and then allow the surface of the compost to dry before watering again. During the Autumn and Winter, keep this cactus dry, giving only enough water to prevent it from shrivelling. This plant will soon rot if kept wet at low temperatures.

Being a native of dry areas, O. trollii tolerates a dry atmosphere. Feed regularly every 1-2 weeks during the Spring and Summer. Use a proprietary cactus food, or one recommended for tomatoes at about half strength.

This cactus will do best in a well-drained compost containing about one third grit. Repot at least every two years.

Sometimes the ‘wool’ on these plants can look untidy, but it can be neatened with a comb if done slowly and gently.


Discolouration: Like many white-spined cacti, this plant can become discoloured when grown in a polluted or dusty atmosphere. Clean a dirty plant by spraying or brushing with warm soapy water. If the dirt has been on the plant for a long time, two or three attempts may be needed. Growing a plant in full sun will also help to bleach out any discolouration.

25. June 2013 by admin
Categories: Tips and Advice | Comments Off on Old Man of the Andes/Oreocereus Trolli


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