Often known also as the Mammillaria Plumosa, the Feather Cactus is nothing like you may expect. Expel the image of a tall, green, spiky thing in the desert from your mind.
No, the Feather Cactus looks more like something your grandmother knitted! But don’t be deceived by the fluffy white and wooly appearance of this succulent.
The white coverage of the Feather Cactus actually hides quite a bunch of sharp spikes!
The Mammillaria Plumosa is marked as borderline endangered, so if you can get your hands on one make sure you keep it well by following our tips in this guide.
Let’s take a look at this truly weird and wonderful-looking cactus together.
Table of Contents
Feather Cactus Care
Generally very easy to look after, the Feather Cactus requires conditions that replicate those of its native Mexico. That means you need a well-draining soil of either a sandy or stony composition. You can purchase this in many garden stores where you will find a range branded exclusively for cacti. Make sure temperatures remain warm year round – below 20 degrees Fahrenheit and it will struggle. Water lightly, once or twice a month. The light requirements of the Feather Cactus are high – adult plants will want to see up to 6 hours of direct sunlight per day. So, locate mature Feather Cacti in a bright and sunny window. Younger plants need a bit more shelter, so they need to have access to ample indirect sunlight. Keep an eye on the soil moisture content and watch for any unwelcome pests, and your cactus will do just fine.
Light
Unlike some of the other cacti we feature on our site, the Feather Cactus loves a good dose of direct sunlight. Mature, adult plants will be very happy to sit in a bright sunny window all day long. In fact, they really need over 6 hours of direct sunlight to thrive and produce flowers. Be careful however of the baby cacti and immature ones. You will need to gradually expose young plants to light.
Best to keep younger plants out of the glare.
Instead, place them somewhere that gets good access to bright indirect sunlight until it reaches the point whereby it can gradually be exposed to more direct sunlight.
Once you feel it is ready for more, you can move it to a sunny location and cover it with a few layers of paper. Remove one layer every couple of days, thus increasing the light content only little by little.
Watering
As with many of our favorite cacti and other succulents, the Feather Cactus needs to be protected from overwatering. The soil makeup is key to this (more on that later) as is a good drainage hole or two.
The key here is to not over water, as any prolonged exposure to excessive dampness will begin to rot the tubercles. We would recommend you let the soil completely dry out in between watering.
This will help ensure your plant has enough oxygen retained in the soil. Excessive watering can clog the oxygen pockets that are found under the surface.
This eventually leads to root rot, and can quickly give rise to fungal infections that will destroy the cactus.
During the winter period, your Feather Cactus will go into a dormant period. At this point, it is important to drastically reduce the amount of water you give it. You can pick up your normal watering schedule in the spring months when the temperatures begin to rise.
Soil
Just as important – and directly related to the watering schedule – is the mix of the soil you use. It is generally recommend to select a soil specifically designed for cacti. You could make your own too if you fancy it.
You will need to mix sand with a potting mix. This will give your cacti the most drainage and also ensure it will adapt quickly to its new environment.
The key is to make sure the soil is well draining, with the aim to avoid root rot. For additional protection you may want to add in some stones too. Make sure you also have a drainage hole or two in the bottom of the pot.
Temperature
Since your Feather Cactus will be kept indoors you won’t generally have to worry about the temperature, especially in winter. It is not a cold hardy cactus, so temperatures lower than 20 degrees Fahrenheit would likely damage the cactus.
Make sure you do not accidentally expose the cactus to low temperatures or frost as this can stunt growth and damage the root system. Once the temperatures dip, you will notice your cactus’ growth slow.
This is natural, and during the winter period you will need to ease up on the watering as it rests.
Flowers
If the white, feathery appearance of the Feather Cactus is not enough for you aesthetically, then wait until you see the flowers.
During the later months of the summer and early autumn you may be lucky enough to get a display of the light yellow, pink or cream flowers typical of this plant.
And a note on the “dormancy” period during winter. Don’t be tempted to artificially keep your plant in the growth period year round. The Feather Cactus needs a time of rest. If you do so, the flowers it produces much later on will be brighter and better quality.
Humidity
Your feather cactus will prefer a lower level of humidity. This means it will do well indoors, especially in the winter months when indoor heating systems make the air quite dry.
Best to keep it away too from the bathroom! If you are experiencing higher levels of humidity then try watering it a little bit less than usual.
Propagation
Propagation of the Feather Cactus is generally pretty easy, and there are a multitude of methods available to you. Since the cactus is becoming endangered in the wild, it’s even more important to maintain its legacy! You can propagate by seeds, cuttings and offshoots, whichever you prefer.
Propagation by seed – Step by Step
You can either purchase the seeds or remove them from the plant just after the flowering season (usually late summer).
Soil: Use a sandy-based potting soil – you can buy these specially mixed, or make it yourself.
Planting: Press the seeds gently into the soil
Watering: Maintain a slightly moist soil until the seeds take hold.
Pots: You will want to move the seedlings to their new (small-sized) pots once they sprout. At this point, you can ease back on the watering and make sure to keep them out of direct sunlight.
Propagation by cutting or offshoots – Step by Step
The Feather Cactus will also produce offshoots, and if it doesn’t, you can propagate by cutting a stem.
Drying the cutting or offshoot: Leave your cutting or offshoot to dry out for a couple of days.
Potting: Place your dried out cutting or offshoot into the same mix of potting soil, and water each time it dries out
Repotting
After the winter period, you should take your Feather Cactus from its pot and ensure that the roots are not becoming crowded. If it looks like they are beginning to ball together, then you will likely need a bigger pot.
If not, it is still good practice to rejuvenate the soil with a new mix, and apply a slow-releasing fertilizer that will do the cactus for the rest of the year.
Growth
The Feather Cactus is not a particularly tall plant. It will likely only grow to around 3 inches in height. However, the width can get to around 16 inches. The bulk of this is made up of the “clumps” that are covered by the feathery or “fluffy” spines. I
t is traditionally very slow-growing, and will do quite well in a container environment as it does not become quickly restricted.
Toxicity
The Feather Cactus is not toxic to animals or humans. Be careful however as underneath its innocent fluffy appearance there can be thorny spikes hiding. Best to therefore not let animals or young children get too close.
Common Problems with the Feather Cactus
This cute little guy rarely has many problems. The main issues you need to look out for are generally applicable to many other cacti we feature on our guides. It is generally disease and pest-free.
Having said that, the unique fluffy exterior makes it more vulnerable than others to particular issues – mainly root rot. And if you do get any unwanted pests or guests, they can be hard to spot given the coverage the “feathers” give to the base.
Root Rot
As we often point out, succulents and cacti do not like to be sitting in damp water. This is especially true of the roots. If you notice that water is pooling in the soil when you water, you need to either reduce watering or check your soil mix.
If too much water gets into the soil and doesn’t drain in time, then your root system risks losing oxygen, which is usually held in “pockets” in the soil.
Fill these with water, and the cactus will soon begin to rot from the roots up. The problem with root rot is that it is hard to identify – given the roots are below the surface – until it is too late. For the Feather Cactus in particular you also need to ensure the feathery parts of the cactus also do not get wet.
Pests and Insects
The main unwelcome pest to appear on your cactus will probably be a mealybug. These annoying insects need to be removed quickly, otherwise they will begin to attack your plant fast.
Mealybugs generally penetrate into the structure of the cactus and spread infections.
Remove at the first sign, and continue to maintain a close watch. If you have a stubborn infestation you might need to treat with a light insecticide.
Under-watering
As long as you water your Feather Cactus every couple of weeks, under-watering should not be a problem. Of course, it is also acceptable to underwater in the winter months.
Sunburn
The Feather Cactus does well even in direct sunlight, but be sure to not expose a young plant to direct sun as this will cause sunburn. Better to keep it in indirect sunlight until it has reached maturity
Frequently asked questions about the Feather Cactus
Why is my Feather Cactus turning brown?
If you notice the feathery part of your cactus beginning to turn brown, check for several things. If it is a new plant, make sure it hasn’t been exposed to intense direct sun. Check the undergrowth for mealy bugs, and make sure your soil is dry
Can I go on vacation without watering my Feather Cactus?
Yes, you can get a couple of weeks out of the Feather Cactus without watering it. Even more in the winter months!
Why is my Feather Cactus not flowering?
Make sure your mature cactus is placed in an area of warmth and good light. The Feather Cactus, when mature, ideally needs up to 6 hours of sunlight every day! So, if you want to give the cactus the best chance at flowering, make sure it is located in a bright location.
Why is my Feather Cactus turning soggy?
This is a red flag. Check immediately that the soil is dry. If not, remove the cactus from the pot and check the root system. If you notice any signs of rot – including odor, discoloration or disintegration, then leave the roots to dry out a few days and repot in well-draining, stony or sandy soil.
Conclusion
Certainly an eye-catcher, the Feather Cactus is always a talking point when guests appear.
During the late summer and autumn in particular the addition of flowers to the white feathery blanket make for a very interesting sight.
Bring one of these home and you can’t go wrong!
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.