The Old Man Cactus ‘Cephalocereus Senilis’

What Is Old Man Cactus?

The Cephalocereus senilis is a succulent lover’s dream and a fan favorite among the varied population of succulents.

Native to the arid regions of Mexico, the old man cactus is a spiky, tall, cylindrical cactus that can reach incredible heights of 10 to 15 meters or more. 

A statement succulent, the Cephalocereus senilis is unmistakable with its shaggy coat of long silver hair, which serves as the source of its nickname – old man cactus. It is reminiscent of an older man’s long unkempt hair.

Apart from giving the old man cactus its unique name and appearance, the long strands of “hair” serve another more critical, less superficial purpose – keeping the plant cool by providing shade from the sweltering sun.

These hairs are not just for decoration. They are a modified form of spines (thorns), and while they may not be sharp enough or hard enough to prick you, they hide a sinister secret.

Concealed below the layer of flowing white hairs are formidable yellow thorns (or spines), and these are sharp enough to draw blood.

Who would have guessed this harmless-looking old man succulent was capable of such trickery and defense?

The bunny cactus is a slow-growing succulent that grows well in pretty hot and arid locations. After all, it is native to Mexico, and last time we checked, Mexico isn’t known for its chilly winters.

Growth

When we say slow-growing, we mean just that. The old man cactus has lovely flowers that will take anywhere between 10 to 20 years to bloom.

However, if you’re patient enough and tend your Cephalocereus Senilis for 10+ years, the succulent gods will reward you with beautiful deep red, brilliant white, or sunny yellow flowers that bloom fully at night.

Not many people get to see the Cephalocereus senilis flowers in full bloom, so be blessed if you are part of the lucky few.

Irrigation

The cactus can be grown both, indoors and outdoors. However, it is more common to see it out thanks to its need for abundant sunlight to grow and develop its hair optimally. When produced in a pot, it is advisable to fill it with a light substrate with good drainage; the pumice is an ideal option. But if you are one of those who like to prepare your substrate with a little fine gravel and black peat you can make an excellent substrate for your Cephalocereus senilis. If we want to plant it in our garden, the soil must be equally light. It must not accumulate waterlogging since the Old Man’s Head cactus will not be able to withstand a flood. To take the appropriate precautionary measures, you can dig the hole to plant it and fill it with a little substrate to ensure better soil drainage.

Regardless of the type of crop that we want to give our Cephalocereus senilis, we must consider that water drainage is the most crucial factor. No water must remain. We can use some other materials so that our substrate is safe. And it has adequate drainage which is coarse sand or washed river sand. Which are quite mineral and are not compact since they can rot at the root quickly.

The Old Man Cactus Care Tips

#1. Weather Conditions

The solar explosion is essential for the “Old Man’s Head,” so it should ideally be outside. It would be best if you gave it sunlight, preferably direct sunlight, for long periods. If you are not used to directing exposure, it is best to acclimatize it little by little to avoid damage from burns. The importance of this intense and prolonged exposure is its characteristic hair. These hairs protect our cactus against harmful rays. Besides, the direct Sun helps them grow faster and more robust. The cultivation in totally shaded places can result in partial or even total paralysis in the growth of our Cephalocereus senilis.    

Despite being a cactus and needing direct and prolonged sunlight, the ideal temperature of the “Old Man’s Head” is not very high; it is around 59ºF, being able to withstand interior temperatures of up to 68ºF without significant problem. When the cold and winter seasons arrive, it would be convenient to keep it in a fresh and dry part inside the house. There are adult specimens in the wild capable of facing 32ºF during these freezing times, depending on their age and size. The cactus should not be exposed to such low temperatures or frost, during the first years.

#2. Soil

Cephalocereus senilis will do well in a quick-drain soil mix with significant aeration and drainage properties like most succulents.

Check your local gardening store for pre-mixed cactus or succulent soil; the cactus mix boasts excellent porous and drainage capabilities.

If you’re more of a “hands-on” kind of guy, you can make your soil mix from home, as detailed in this article by Succulent City’s in-house botanical experts:

Learn how to DIY your planting soil at home:

#3. Watering

Like any other succulent, the old man cactus isn’t too fond of over-watering. After all, it is endemic to Mexico, and last we checked, Mexico doesn’t make the news for its lush green, rain-soaked plains.

Beginners usually make the mistake of watering their succulents daily. The result is always the same – over-watering leads to the dreaded root-rot, killing the poor succulent.

Read more about root-rot in this informative article by Succulent City:

#4. Fertilizing

The spring and early summer seasons are ideal for fertilizing our Cephalocereus senilis. We should provide him with a mineral fertilizer rich in lime or a standard cactus fertilizer to grow his characteristic “white hairs.” Still, it is essential to be careful not to overdose. Flowering occurs in older cacti more than 15 years of age and usually occurs only outdoors; it is almost impossible to flow in indoor specimens successfully. Its flowers arise from a very hairy body developed on the stem’s sides; they are tubular flowers with red, white, and pinkish pigmentation. These flowers usually fully bloom at night.

Cephalocereus senilis can be easily propagated from seed. It is preferable to do this during spring or summer. We must place these in trays with a cactus substrate. Keep them in a bright area with enough indirect light and water so that the soil remains moist. If everything goes well, we should have germinated seeds between ten and fifteen days after planting them. The “Old Man’s Head” cactus needs to be transplanted every two to three years. During the spring, it into a larger container to provide it with a renewed space to grow.

#5. Planting and potting

Most succulent growers plant the old man cactus in a pot (preferably terracotta) and leave it outside during the summer and spring seasons, where it can soak up its fill of sun.

When winter rolls around, they carry the pot indoors and place the succulent under grow lights as a substitute for sunlight.

Sunlight stimulates the growth of Cephalocereus Senilis long silver hair. The more sun it soaks up, the thicker and longer its silver hair gets.

#6. Re-potting

Re-potting this particular cactus shouldn’t be a concern, especially when you factor in its slow growth rate – the  Cephalocereus Senilis grows even slower when potted indoors than out in the wild.

Common practice is to gently loosen the soil around the roots and slowly work the cactus out of the pot.

Inspect the root system – when you notice the roots wrapping around the bottom of the root ball, it is about time to move this succulent to a new, slightly larger pot.

#7. Pruning

This type of plant almost does not need any pruning. Naturally, the old man cactus grows slowly in a straight line, and with the help of its dense hairs, the plant is protected from the changing weather. In terms of appearance, the old man cactus is neat looking. You may only need to prune your succulent to maintain its size or shape. Instead of pruning, what you can do is spray water, comb, and clean any insects or dust away from your old man cactus.

What Is Root-rot? How To Fix It

Like any other succulent, wait until the soil completely dries out before watering it through and through. When you finally water the old man cactus, soak it through but do not drown the poor guy or leave it sitting in stagnant water.

Succulent cultivation 101: Succulents despise stagnant water.

Pests

The old man cactus is prone to the occasional nasty critter here and there because its long shaggy strands of white hair provide a perfect environment for these pests to hide and nestle in.

Something similar to how lice love to hide in long unkempt hair.

Look out for mealybugs, spider mites, and scale.

Propagation

Propagation By Seeds

The old man cactus is a pretty easy succulent to propagate from seeds – a fact that saved it from extinction a few decades back.

Its ease of propagation and increased cultivation by succulent lovers supplemented the otherwise depleted Cephalocereus Senilis that had been growing (dying really) in the wild.

You can gather seeds from its fruit; however, it’s simpler and faster to buy them from your local gardening store or a reputable online vendor due to this succulent’s slow growth rate.

Propagation By Offsets

This method is considered the easiest way to propagate the old man cactus. Remove the offsets from their mother plant using your hands or a clean, sharp knife. If you are removing the offsets by hand, wearing gloves or having a protective barrier is advisable to avoid getting cut from your succulents’ spines.

Ensure you gently uproot the offsets to avoid damage to the offsets and the mother plant.

Allow the offsets to be calloused for two to three days before planting on well-draining soil. Allowing these to be calloused avoids the risk of bacteria or fungi.

Propagation By Cuttings

Aside from using the seeds and offsets of your old man cactus, you may also propagate it through its cuttings.

You may let the cuttings be calloused like offsets before planting in a well-draining soil mixture. It is advisable not to water your newly planted cutting until it has been rooted. After a few weeks, once it has rooted, you may regularly take good care of your old man cactus

Where To Find Cephalocereus Senilis?

Ask your local gardening store supervisor whether they stock  Cephalocereus Senilis seeds.

Home Depot and Lowe’s pack an extensive range of succulents and cacti.

Swap meets and flea markets remain our favorite places to go succulent shopping.

We highly recommend you visit these open-air markets. They are the perfect place to source obscure succulents at pocket-friendly prices.

If you’re unable to leave the house for whatever reason (ahem, coronavirus, ahem), then you can opt for online shopping:

• Buy the Cephalocereus Senilis from Etsy for $22.36

Final Words

All in all, aside from Old Man Catus’ tall, hairy, and sparkly silver appearance, we hope that you will be able to understand better how to take good care of this plant. A variety of succulents are available out there for you. We hope that through this article, you will get to know Old Man Cactus better and consider it your next plant baby. This beautiful succulent is also easy to grow, making it a perfect choice for those busy plant parents or new to having their house plants. Thank you for reading through this article, and we hope you keep your eyes open for other unique succulents as well!

ABOUT ME

Richard Miller

Salute everyone. It's Richard, the author of this Succulent & Xeriscaping blog. I am a traveler and a nature lover looking for a connection with the wild green. In my journey, I found a love for succulents and xeriscaping. What attracts me is the long-lasting & unique beauty of every plant I have the chance to see with my own eyes. Welcome to my little blog and let's enjoy a good time together!

Contact me: richard.succulentcity@gmail.com