One of the most common issues with growing cacti and succulents is the problem of etiolation.
But what is it, and why should you care about it?
Etiolation is an effect from growing a flowering plant in too little light, whether that’s just not quite enough or even full darkness. To try and find enough light to grow and survive, the growth point on plants will stretch and reach towards a light source.
Etiolation is characterized by long, weaker stems, smaller leaves and longer internodes, and a much paler color than usual, often very yellow.
If you’ve never realized what it looks like before, or you’re not quite sure how the plant you’re growing is supposed to look, it can be hard to spot what it looks like. This is doubly true in northern climates, or if you don’t have the same access I do to botanical gardens will well-grown plants. The Copiapoapictured above is one of the saddest examples of the species I’ve ever seen, and it was in a European botanical garden!
Why is etiolation bad for your cactus or succulent?
When etiolation occurs in seedlings or faster growing, more tropical species, it’s more of an inconvenience or an eye sore than it is a major issue. It’s a signal to adjust your lighting or the plant won’t look as nice, but it’s a fairly rapid and easy fix.
In cacti and succulents, however, by the time you’ve noticed the etiolation it may be too late.
For this post, I’ll focus on etiolated cacti and how you can prevent a similar effect. Next week, I’ll share a post about succulents to help you identify your etiolated succulents and how you can fix or prevent the same effects.
At left, you can see one of my Matucana madisoniorum – it’s blooming, the growth point at the top is slightly concave, and at first glance it seems fine.
But if you look again, you’ll see a small “waist” in the plant.
There was a period where it didn’t get enough light while it was actively growing, which resulted in narrower growth as it stretched towards more light. Once it got that light, it returned back to “normal” growth, resulting in a bit of a pinched waist.
In this case, it’s purely aesthetics: the cactus is imperfectly grown, so I can’t enter it into any cactus shows. It’s still healthy and producing flowers and seed for me, though, so it’s not a loss.
In more extreme cases, the etiolation is the prelude for a level of damage that’s only going to result in death for the plant – maybe not that week, but in the coming months .
The process of etiolating weakens the plant overall, more than just making it look unattractive. The thinner, stretched growth is more prone to rot, pests, and physical damage such as sunburn or simply falling over.
With succulents, you can often recover the plant: move it to brighter light, wait for the newest growth to de-etiolate, and then behead it and re-root that part. I’ll detail this more later, but it’s a much easier fix.
With cacti, unfortunately, you can’t usually do that. My matucana above, for example, can’t be cut off at the healthy growth and re-rooted. That would just kill the plant. The new growth will look normal, but the etiolated portion never becomes un-etiolated.
Identifying If Your Cactus is Etiolated
To the experienced eye, it’s extremely easy to spot that a cactus is etiolated (usually). The more plants you see, especially healthy ones, the better you get at identifying if one looks the way it should or not.
But if you’ve never had the joy of exploring a well-kept botanical garden, or visiting someone’s collection in person, and all you’ve seen are slightly sad big box store plants? It’s entirely understandable if you’re not sure if your cactus is stretching and etiolated or not. Here’s a few example to reference, alongside how the cactus *should* look, or a similar species.
Etiolated
Not Etiolated
How do I know the one at the left is etiolated, even though it’s blooming and has the indent at the top that usually indicates adequate light?
Look at the body of the plant and the one behind it: they’re both sort of wavy, with pale green flesh and inconsistent spacing for each row of spines.
Contrast the plants on left to my similar rebutia species on right – dense, even growth, and a darker base color you almost can’t see behind spines.
The etiolated plants at left may limp along, sometimes for years, but they will rarely thrive and look as attractive or produce blooms as prolifically as a well-grown cactus. The ones at left will be more susceptible to pests, and significantly more prone to rot due to weaker cell walls.
If it’s a beloved plant, then you can likely baby them along, probably for quite some time. They will never recover, though, and will never look right. To fix it, you could try acclimating the cactus to brighter light, letting it grow ‘properly’, then when it’s got a couple inches of proper growth you cut that off and root it. For this type of cactus, that’s a pretty drastic approach, and very risky if you’re a novice to rooting cut cacti (very different than rooting pups).
Etiolated
The cactus at right is the one I’m comparing here; both species shown in the image are extremely etiolated, however.
Not Etiolated
At left, you can see the extremely stretched, desperate growth of severely etiolated cacti. The left photo, with the cacti in the yellow pot, has a cactus on the right that is the same (or nearly enough) species as mine on the right.
Notice the increasingly narrow growth, how the new growth is much paler than the old growth, even in the shade and bad lighting of the photo. At right is my similar species, an echinopsis hybrid, as a younger plant. While the top is narrower, each new areole of growth is consistently spaced, and the top is slightly concave. At this size, these cacti should have a slight indent at the top – if it’s starting to bulge up, or look like someone has tugged the top of your cactus and it’s narrowing like a piece of dough, it’s etiolating.
In the photo at left, the cactus on the left could be recovered. It’s an opuntia species, and just breaking off a paddle, setting it on soil, then keeping it in bright indirect light until it roots would do the trick. Once you get some nice healthy looking pads, repeat the rooting process with those for healthy younger plants. The stretched growth is doomed; it will never look better, is very weak, and extremely like to get rot or pests.
In the yellow pot at right, I’d personally consider that cactus to be doomed entirely. You may be able to move it to more light, and get some pups before it succumbs to that weak growth rotting out.
How could this have been prevented?
The person growing these likely thought they were doing well; if the cacti were in this placement all the time, shaded but outside, it seems reasonable.
But this is a classic example of listening to your plants rather than what “should” work. Both of these cactus species need nearly full sun, and in the midwest (where I belive this person is from), they’d need to be out in full sun as early as possible in the year and brought in to overwinter as late as possible.
This level of stretching looks like either a poor over-winter period indoors, with no supplemental lighting and the cacti not kept cold enough to go dormant, or the person has kept them in almost full shade under a covered patio.
These are both that same plant, but several years later. This type of cactus gets tall and a little goofy looking with age. The top is still slightly concave, you can see even spacing in the spiny areoles, and it’s a deep green color. This is just how the plant looks when it’s nearly 10 years old!
Etiolated
Not Etiolated
So these are two very different species, but I wanted to contrast the placement of these Monkey Tail cacti.
A Monkey Tail cactus has evolved to thrive in nearly full sun; they don’t look their best unless they’re kept extremely bright. The one at right was in a greenhouse up in Ramona, hung up at the top of the giant dome to trail down. This means not just bright light, but also one of the hottest placements in the greenhouse (the whole “heat rises” thing).
The person at left has theirs indoors, by a window with blinds, sharing space with tropical plants. They had commented in the Facebook group I found this in that the etiolation happened after they brought it home, and when you consider the contrast in care – it’s easy to see why!
And for contrast, here’s my Monkey Tail cactus, which is likely the same species as the lady’s above.
Why’s hers etiolated, but mine isn’t? Why am I pointing out hers vs mine?
In hers, look at the new growth – it’s narrow, getting that “pulled on some dough to stretch it” kind of appearance. It’s hard to tell in the photo, but I’d bet the new growth has really widely spaced areoles, no consistent rows, and that the cactus’s body is much paler on the new growth than it is on the older growth.
Mine at left, while growing like an absolute wierdo, still shows consistent space between each spine group. The newest growth has the shortest spines and least development of color and length, but that’s typical for the species – which I know from having seen others grown at friend’s greenhouses!
I just moved mine outdoors to a nearly full-sun spot in the front yard. I’ll write up a grow diary post about it soon!
How could the etiolation have been prevented?
The person with the etiolated Monkey Tail cactus should have had it outdoors, in full sun or close to it, from day 1. These are not indoor plants unless you’ve got giant, floor to ceiling windows and constant sunlight. If you’ve never stared at the room and wondered if it should get its own AC unit because it gets so damn hot from the windows and sun hitting it, the room won’t work for this species, full stop.
You *might* be able to get around this by providing the cactus with its own grow light, but you’ll need to use the big guns. Don’t even think about those flimsy pink and purple ones – you need the weed grower’s deluxe.
Or, just stick it outside. These are perfect to hang on patios that face south or west, thriving as they do with the bright light. The more light and heat they get, the happier they are.
Caveat? They can’t freeze, and they don’t really go dormant. If you get winters where it’s cloudy and daytime highs stay below 50F, you’ll have to look at options for wintering your Monkey Tail indoors.
Same Monkey Tail cactus, but repotted and placed out front. You can see that with more sunlight, the fine hair-line spines have become longer, and the new growth at the ends of each branch are much more protected by spines. The far right arm actually detached from the main plant body and I’ve left it weighted down in the pot to try and root, but the arms at left all have plump bases, with consistent spination and growth through the full body of the arm.
Something to point out in mine – it was not getting enough light, even in the greenhouse! Notice how the very top monkey tail (the fuzzy one from the Ramona greenhouse) has long arms that point DOWN? And in the etiolated one as well as my own greenhouse-grown plant, the arms start pointing UP? The growth point on these cacti shouldn’t be nosing up towards the sky – in this species, that’s a sign of inadequate light.
Now that it’s outside under full sun, all the arms and new growth are pointing down. New arms emerge and point up as they come out, but as soon as they get length, down they go. This is an adaptation to protect the delicate growth point at the tip from direct sun. So…if yours isn’t trying to shelter the growth tip of the arms from too much sunlight, it’s not in a spot that’s brightly lit enough.
Etiolated
Can you spot which cacti in this terrarium are etiolating, and which aren’t?
Let’s chat about why this is happening, shall we?
Not Etiolated
At the left, we have a common Crime Against Cacti: planting them in a terrarium and expecting them to thrive.
But interestingly, not all of the cacti in that terrarium are obviously etiolated. They all will, over time, or they’ll just die – but why are only some showing the signs?
The fuzzy one in center is the most obvious, and the little opuntia behind it is also showing signs of new growth being etiolated. The two cacti at front look fine, and I’d bet they look almost exactly the same as they did when the person potted them up.
Does this mean they’re all getting inadequate light, or just some?
They’re all not getting enough light. The big difference is the speed at which some of these species grow compared to the others, and how tolerant they are of poor growing conditions. The front right cactus, the little globe thing, is a little Gymnocalycium anistisii (probably), and it’s not growing because it’s miserable. It’s sitting there, being green and not producing new growth, because it’s waiting for conditions to get hotter, brighter, or both.
The left cactus in front is probably a Stenocereus pruinosus, a “Gray Ghost” cactus – and I actually stopped carrying these in my Etsy shop because I found them to be super finicky once they left the nursery. In ideal conditions, these are slow growing but impressive columnar cacti that are beautiful once they reach size. A little glass terrarium on a windowsill is far from ideal conditions, and I’d bet a not-insignificant amount of money the cactus in this photo is rotted at the root base and is just secretly dying.
In a way, having these faster growing species mixed with the slower ones is a good thing! The opuntia in particular makes for a good “signal plant” to tell you conditions are too dark before your other cacti truly begin to suffer. They’re fast growing enough that you’ll see, quickly, that the conditions aren’t ideal. This gives you early warning before a more precious and slower growing cactus rots or stretches as well.
How could this have been prevented?
For someone really determined to grow cacti in a terrarium type of setup, quality grow lights would be absolutely necessary. The glass of the terrarium and lack of drainage combines two very challenging elements to cactus growing: extremely high heat when the sun hits, including on the roots, and no way for excess moisture to drain out (and nowhere for salts and mineral deposits to go, either).
Success with this type of arrangement would have been better with a true terrarium – something with a dedicated light, layers of substrate and soil, and smaller maturing species that would have been happier in cramped quarters.
If the goal was to grow each of these cacti to look the best they could for their species, they needed individual pots and to be outdoors in nearly full sun. The Gymnocalycium is the only one that may have done well as a windowsill plant, assuming the window was south-facing with no shade at all.
Etiolated
Not Etiolated
These two opuntia aren’t the same species, but they share similar growth patterns and appearance.
The one above is brilliant green with tons of new growth. The one at left also has a ton of new growth, and it’s bright green, but it’s very clearly etiolated.
While there are some species of opuntia that get tall and lanky, and that’s just how they look, the tiny little finger-growth paddles are absolutely not normal.
The one at left may have been etiolated even with the original paddle, it’s hard to tell. The newest growth for the plant is definitely etiolated, with inconsistent, stretched-looking growth, paler green color, and most telling – the need for support just to exist the way the plant should.
Meanwhile, my juvenile tree-opuntia at right, has tons of new growth! It’s tender and pale green, but it’s a more oval shape, with consistent spine patterning and density. I chose this plant as the comparison because the species is chaotic at best, and often produces odd sized and shaped paddles – but the density of growth, the quantity of new growth, and that it resembles other successful plant shapes (like bushes) are all signs that it’s receiving enough light.
It’s not immediately visible in the photo, but within a few weeks as the paddles of new growth began to harden off, the spines absolutely exploded on that cactus. In cacti, heavy spination is a protection against bright sunlight, and seeing dense spines developing is a good sign of the plants receiving excellent light.
You should be able to see the giant tree opuntia behind the columnar cactus in the foreground; that’s the “mother plant” for the other opuntia. It produces floppy, flappy paddles and the appearance is generally chaotic.
Importantly though, this particular plant is in full sun, is easily 20 feet tall, and has been thriving for decades.
The little potted opuntia with its sad little finger growths? Less established.
The person growing that plant can and should be forgiven for not realizing that type of growth is not ideal, as I think the species was a non-variegated Opuntia monacantha, which is a scraggly, floppy growing species. It’s really only popular because the variegated form can look quite beautiful.
At right is the variegated form of Opuntia monacantha, and it’s cool – in sunshine, it’ll blush some pink hues, and it’s got the pale color and variegation that the cultivar is known for.
Does it look weird and lanky to you too? Like it maybe could get tossed in the etiolated bucket based on some of the earlier photos I posted?
It’s not. It’s just ugly.
That’s where seeing lots of different cacti, googling the species you’re picking up, and researching comes in super handy! This particular species is just plain weird. It can still produce etiolated growth that is noticeable (mainly for looking like cactus spaghetti), but the natural, healthy growth of this cactus is a shape that might look etiolated to an inexperienced eye.
The plant at right grows in full sun, 100% sun, all the time on the top shelf of my inventory rack. It gets no shade, ever, and still looks lanky as hell.
If the goofy, lanky appearance appeals to you – fantastic! Snag plants like this, and keep them in full sun.
An important note though: see the spines? Even at the top? Lanky this may be, but the spines are evenly spaced and they exist. The etiolated version above has almost no spines, indicating it’s not receiving enough light to encourage proper spine development.
In-ground, these types of cacti tend to be fine, and able to support their own weight. I believe they slowly develop trunks, like my giant tree Opuntia further up, but I’ve never grown one of this species long enough to see. In a pot, I’ve found them to be very likely to get blown over by wind or otherwise knocked over, which makes them less than ideal container cultivation candidates in my opinion.
Etiolated
Not Etiolated
I’ll wrap this post up with an advanced-level etiolation spotting.
The one on left is etiolated; the plant at right isn’t. What’s different?
The cactus at left shows inconsistent growth. You can see a waist on some branches, and the top of the cacti are pale green and look stretched compared to the lower parts of the cactus body. The top in particular is the most worrisome and etiolated looking; spine density is much lower and that color is not a healthy color for a cactus body.
Meanwhile, on right, is a species that has a common name of ‘golden ball cactus’. The cluster is clearly growing in columns, and not ball shaped.
Don’t mistake the plant for golden barrel cactus, like Google seems to. The plant at right is Parodia leninghausii, and despite the name, it’s a smaller columnar species that can reach up to 3 or 4 feet tall with time. You can tell that the cactus pictured is growing as it should in a few ways:
- Top is slightly concave, despite looking flat from the side
- The tops you can see into have a clear tuft of spines coming out from the center, very prominent and bigger than the rest.
- note that for cacti, spines are often protective covering for new body growth. Heavy spination at the center/top growth point is an indication of proper light
- Growth is consistent, and a slight spiral can be seen in the ribs of at least one cactus. I moved this cactus in the greenhouse often, so a proper sundial spiral wouldn’t happen, but consistent ribs, spines, and areoles that do spiral (indicating that the plant was following the sun for multiple seasons) are signs that point to proper light
- Darker green flesh on the body of the cactus – the color of the body of the cactus is consistently a dark, constrasting green compared to the spines. When you look at the cactus at right compared to the one at left, the color of the left cactus is sickly and pale in comparison
I’ll admit that because I didn’t research my Parodia leninghausii very much before sticking it in the greenhouse, I thought it would grow as a cluster of globe-shape cactus heads. As time went on and it began to grow up, rather than producing pups or as a larger ball-shape, I got worried! I thought it was stretching, etiolated, that I was messing up the care.
Nope.
They’re just weirdly named small columnars. The species doesn’t stay as a ball shape.
And that’s what I’ll leave you with. Research your species, and understand their growing conditions. Some are sprawling, ground-cover-esque cacti that thrive with brutally bright sunlight, and would suffer in partial shade. Some are better equipped to grow in partial shade, but would love more sun.
A sprawling, ground-cover type of cactus in a large species-suitable planting at the Huntington Library gardens in Los Angeles
It is very, very rare that a cactus will thrive in a windowsill setting without some sort of supplemental help, especially in winter. For my northern latitude readers, investing in a quality grow light and stylish housing for the lights is a minimum requirement. Save yourself the heartache and trial and error; get the Real Deal™ lights and set them up to look nice enough for the season.
I am very fond of these lights as a replacement for regular bulbs in lamp stand or similar appliance. They work extremely well for my tropical plants indoors, and might be enough to supplement windowsill cultivation in winter for your cacti. I’ll say, though, any northern latitude growers I know trying to cultivate cacti invest in a larger, dedicated setup for the plants during the worst of winter.
At left is the saddest copiapoa I’ve ever seen in my life, spotted at a botanical garden in Rotterdam.
It was likely a poached plant, originally, especially if you consider the red lichen growing in a large spot on one side.
But the shriveled, dehydrated growth, and weird lumpy new growth at top combines to just be…sad. In the Netherlands, cacti like this need supplemental lighting at least half of the year when days are very short. Adapted as they are to extreme daylight hours, cloudy weather and short winter days are brutal for them.
A general rule of thumb for your indoor cacti, experiencing only a consistent, never-changing exposure to light, is to provide that light for at least 12 hours, preferably 14. Use a light meter to check that the light exposure is at least 800 foot candles to start, preferably more like 1000+.
Etiolation is something you’re bound to encounter at some point or another as a cactus grower. The more you learn, experiment, and test positioning and placements, the more likely you are to put something in a spot that doesn’t work.
And that’s okay!
Practically speaking, if somewhat cold-hearted, is to intentionally get a faster growing and tolerant species and use it as a litmus test for your placements. Opuntias grow in spring, so use a small bunny ear cactus or similar to test your spring placement. Cereus species grow all through late spring and summer, and will work to help spot if your summer positioning isn’t bright enough.
I wish you the best of luck in your cactus growing endeavors, and please – share your cactus photos with me! You can find me on Instagram at @TrexPlants, or simply email me at [email protected].
