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What Is This White Stuff on My Succulents?

“Epicuticular wax”, “glaucous leaves” and “farina” are unfamiliar terms for a common occurrence in succulents, and plants in general. They refer to the whitish, cloudy film or waxy coating you see on a number of succulent leaves and stems. You may have tried to wipe it away, to find it easily wipes clean, but that there was more there than you realized. This is a perfectly natural and healthy development the plant uses for its protection. Because it bears some resemblance to other white substances that are highly damaging, like whiteflies, mealybugs and powdery mildew, it can be concerning. Let’s take a closer look at what this is all about.

Epicuticular Wax | Glaucous Leaves | Farina

{Please note, some links in this post may be affiliate links to sites that pay me a small commission if you click on the link and make a purchase. This commission is at absolutely no cost to you. I only recommend products and companies that I have worked with and truly love! ~Kat}

Epicuticular Wax

dish of blueberries demonstrates epicuticular wax

Epicuticular wax is a layer of whitish film on the leaves, stems and fruits of a wide variety of plants. Among many others, you see it on blueberries, plums, red grapes, apples, kale and many succulents. It forms on the outer cuticle of the plant’s skin. This wax makes water bead up, rather than truly wet the plant. And it tends to cause dirt particles to adhere only loosely to the leaf, so that it easily washes away when a water droplet rolls over it.  The wax helps to keep the part of the plant that it covers from losing moisture to the air. It also reflects UV radiation, acting essentially as a sunscreen, preventing damage to the plant in the form of sunburn. Finally, it tends to make the surface more difficult for insects to walk upon it, or to lay their eggs on it.

Epicuticular Wax on Succulent Leaves

Echeveria Perle von Nurnberg with epicuticular wax

Plants develop epicuticular wax to enable them to thrive in challenging climates. For succulents, this wax helps to maintain their stores of moisture during times of drought. It helps the plant to grow in full sun without damage, and to protect it from insect predation. For some plants, like camellias, the epicuticular wax gives the leaves a glossy appearance, with a high shine. In succulents, most often it is a soft, powdery appearance referred to as glaucous. Many succulents are described as having “glaucous leaves”. In botany, glaucous leaves are any that are “covered with a greyish, bluish, or whitish waxy coating or bloom that is easily rubbed off”. Most often, the succulents referred to as glaucous are those that have bluish-grey or green leaves with pronounced epicuticular wax.

Succulents with Glaucous Leaves

Echeveria imbricata with glaucous leaves

Many varieties of succulents have a pronounced epicuticular wax on the leaves. Ecechervia imbricata, the lovely blue rosette succulent above, may be the best known. You will also see this whitish wax on many, many others. It tends to be so pronounced on kalanchoe thyrsiflora, the flapjacks or paddle plant, that people often seek help for the condition, not realizing it should be there. The white chalky dust can cake up quite a bit on the stems and the lower part of the leaves. This is not a problem, and it should be left in place to continue to do its job.

Don’t Wipe Away the Wax

Echeveria lilacina with epicuticular wax

Because epicuticular wax provides so many benefits to the plant, it should not be wiped away. Further, it takes a very long time to come back, in succulents. The plant tends to look a bit patchy, where the wax has been removed, and will remain so for months. Choose instead to see the beauty this natural protective layer imparts to your plants. It produces an almost ethereal quality to the color, doesn’t it? Use an inexpensive paint brush with soft bristles to remove soil from your succulents, or to brush away dust.

Recognizing Epicuticular Wax – Farina

Kalanchoe luciae with epicuticular wax

Recognizing epicuticular wax, and discerning the difference between it and a pathogen or infestation lies in its purpose. This wax serves as a sunscreen, a protection against water-loss and against insects. So clearly, it will need an even “application”, right? In fact, the term “farina”, (often used a bit inaccurately as a synonym for this type of wax), refers to an even dusting of very fine powder. Once you know this waxy powder is supposed to be there, you will note how evenly it covers the plant. It develops on the underside as well as the top of the leaf, and equally on every leaf of the plant. And if there are locations of heavier accumulation, they occur in a very gradual fashion that appears intentional. This is an important look to recognize, as the appearance of powdery mildew and of whiteflies lacks this. Also, since this wax protects the health of the plant, make note of the condition of the leaves. Healthy, happy leaves with a very fine, very even dusting of powder that covers the entire plant is a good description of the look of epicuticular wax.

MaryCarol Chapman, a wonderful member of my Facebook groups for succulent-lovers (you should join us!) has a fantastic suggestion I have adopted for succulent care that is prefect for identifying issues of white stuff on your succulents. As she suggested, I now include a jeweler’s loupe in my bag of succulent tools. The loupe let’s me get a really good look at any white stuff, so I can better see what it is made up of. If I see little legs, I know it is an insect and much be addressed, (see below). It a gives me a chance to better evaluate the fine texture and even application so I can better distinguish epicuticular wax from powdery mildew.

Recognizing Powdery Mildew on Succulents

Powdery mildew on pumpkin leaves.

Powdery mildew is a fungal disease that can harm your plants. Over time, it leaches nutrients from the leaves, causing them to yellow and wither and drop. It is highly contagious and can affect any type of plant. It appears white and a little furry or fuzzy. As you can see in this picture, it can look somewhat like the beneficial epicuticular wax. But there are notable differences. Powdery mildew forms gradually, and it tends to start on a single leaf or two, heavily covering those leaves while neighboring leaves have little to none. So it is not evenly distributed over the plant at all. Close inspection shows it to be a bit patchy rather than so even and fine as the wax.

If you are concerned that you have a plant with powdery mildew, it is important to take action. To confirm that this is the problem, if you are unsure, take a leaf to a local nursery to have someone look at it for you. Or ask an experienced gardener, or take a photo and ask others on Facebook gardening forums for confirmation. If you are battling powdery mildew, there are a number of natural and effective remedies. I highly recommend this article as a great starting point for remedies for powdery mildew.

Recognizing Whiteflies on Your Succulents

Whiteflies on Sempervivum

Whiteflies are tiny insects that suck the moisture and nutrients from plants, leaving a sticky residue called honeydew behind. Leaves soon wither and deform with a whitefly infestation. The insects and larva are all white, and sometimes look fluffy or furry when they accumulate. The eggs are a pale yellow when freshly laid, and brown when they are ready to hatch. Whiteflies tend to be more active on the bottom of the leaf than the top. And they do not produce a uniform, even, superfine coating of the leaf or plant like the epicuticular wax does. The honeydew they produce is sticky, attractive to ants, and a helpful way to determine that the issue you have is whiteflies.

If you are concerned that you have whiteflies but want a second opinion, the local nursery, gardening friend and Facebook forums will be very helpful. Read more about whiteflies and how to control them here.

My preferred method for both treating a whitefly problem and preventing one from occurring is to use worm castings. Worm castings are essentially worm manure, and they are rich in minerals that make them a wonderful organic fertilizer for succulents. Among many sterling qualities, worm castings are a natural source of chitinase, an enzyme that breaks down the exoskeleton of insects. I incorporate dry worm castings into the soil when I plant a succulent, either in a pot or in the ground. This enables the plant to take in the chitinase through its roots and distribute it throughout the plant. Whiteflies and other pests sense the chitinase and avoid feeding and nesting on those plants. A worm casting tea can be applied topically as a foliar spray to treat an infestation of insects – and fertilize the plant at the same time.

Thank you, Lindsy Hemmersbach, for the use of this photo!

Recognizing Mealybugs on Succulents

Closeup of a single mealybug on a houseplant

Another example of white stuff on your succulents is the dreaded mealybugs. Usually, the first sign of mealybugs is a fluffy, white mass of cottony-looking stuff on the stems, petioles (the short stem-like structures that attach the leaves to the stem) and the leaves. The fluff generally looks a bit ratty or disorganized, and often includes black specks — the insects’ droppings.

Mealybugs are slow-moving, soft-bodied insects related to scale. They feed off the stored moisture in a plant’s leaves, and they just love succulents. While they move slowly, they reproduce rapidly and an infection can quickly become an infestation. Mealybugs secrete a sweet, sticky substance called honeydew that both attracts ants and feeds and supports sooty mold on your plants.

Like whiteflies, mealybugs are best prevented with worm castings. You can also kill existing mealybugs with a direct spray of isopropyl alcohol (rubbing alcohol). It won’t hurt your succulents, if you spray them out of direct sun, and leave them protected from the sun for 24 hours. Spray the plant heavily, protected from direct sun until it is thoroughly dry.

Echeveria and mixed succulents with epicuticular wax

Now you know the purpose of that white film on many of your succulents! It is epicuticular wax, sometimes called farina. Even better, you can better determine if the powdery white you see is friend or foe – a beneficial wax or signs of pathogen or infestation. In general, the wax will be very fine and very evenly distributed on your plant, where the powdery mildew and whiteflies will be more patchy in appearance. Good plant hygiene is the best defense against mildew and bugs. And embracing the beauty of glaucous leaves and their waxy coating will help you to enjoy your healthy succulents!

I hope you found this article helpful. Please take a moment to leave a comment if you have any questions, or feel free to send me an email!

Happy Succulent Gardening!

P.S. For more succulent care information, please subscribe! I’ll send you my FREE course, 7 Steps to Succulent Success. Thank you!

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P.P.S. Why not join my Facebook Group for succulent-lovers? We talk succulent care, propagation, succulent identification and design. It’s a warm and welcoming group that would love to meet you!

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This Post Has 28 Comments

  1. Deborah De Vries

    Great article. Love the botany – may have to study up!

    1. Kat McCarthy

      Hi Deborah,
      Thanks so much! I always find it so much easier to learn something new when I understand the why behind the what. I’m glad you find it helpful, too! 🙂

  2. Elaine Olson

    I recently joined your very informative emails…love the learning. I have a succulent similar to Graptosedum Darley Sunshine and it developed black tiny bugs on the bloom. I used a soap spray and it developed spots…what did I do wrong? It looks awful now.

    1. Kat McCarthy

      Hi Elaine,
      Thanks so much for the comment! 🙂
      Let’s figure out how to deal with your insect problem. Ugh!
      It doesn’t sound like you did anything “wrong”… An insecticidal soap is a great first step to take when dealing with insects. Would you be able to send me a photo of your plant now, and the spots it has? I will be happy to help!

  3. Carolyn Stephens

    Thankyou for your helpful info.

    1. Kat McCarthy

      SO glad you found it useful, Carolyn! 🙂

  4. Hey Kat, just a heads up – the picture you show here of the Sempervivum with whitefly is actually the cast off skins of aphids which undergo a series of ‘instars’ where they shed the skin to allow them to grow. Whitefly damage usually shows up as sticky ‘honeydew’ on the leaves (the poop of the whitefly), which then feeds black mold.

    1. Kat McCarthy

      Hi Jacki,
      Oh – thank you for the clarification! I mislabeled my image. Thank you!

  5. Holly

    I have a succulent that has this almost spiderweb liked white coating around the stem of it and it’s kind of falling naked in that area and becoming very weak and it’s on the leaves as well some of them ,and some of them are turning to Death,? can you tell me what this might be
    thank you

    1. Kat McCarthy

      Hi Holly,
      It sounds like your plant may have mealy bugs. If so, you need to treat it to eliminate the mealybugs right away. Can you send me a photo of your plant? Send it to kat [at] the succulent eclectic [dot] com.
      I’ll be happy to take a look to better advise you!

      1. Charley


        I got a new succulent the other day and loads of the white powder has been rubbed off. Will it eventually return? I’m so upset as it looks so bad now 🙁

        1. Kat McCarthy

          Hi Charley,
          In time, the plant may be able to develop more wax to replace that which was wiped away. But not to worry – new growth will have it.

  6. Usha Hafiz

    Thankyou so much, for your blogs. They are very informative. I have learnt so much about caring for succulents, and feel more confident in caring for these precious plants

    1. Kat McCarthy

      Thanks SO much, Usha!
      So glad you find it helpful!

  7. Jennie Robinson

    Thanks Kat. Thought my Gremlin had developed powdery mildew (I live in a rainforest in North Queensland,Australia and we have had some winter rain) but it was so even I think you are right about the wax and next time I won’t go into panic mode. Love getting your posts as they are so informative and easy to understand. My succulents are under cover because of our rainfall but get the morning sun. Jennie

    1. Kat McCarthy

      Thanks, Jennie!
      SO glad you find the information valuable!
      It can be tricky to verify what is natural and what is a problem! 🙂
      Thanks so much for subscribing!

  8. Gail Williams

    That was a really informative post. Thanks Kat.

    1. Kat McCarthy

      Glad you found it useful, Gail! 🙂

  9. Heidi Houseman

    I would love to send you a picture of something on a succulent I have. I think I understand the powdery coating that is protective thing. Maybe that is what I have on my succulent, but not sure. It wipes off easily – is not sticky, has not spread, would love some help.

    1. Kat McCarthy

      I’ll be happy to help, Heidi!
      Please send me your photo by email to:
      kat [at] thesucculenteclectic [dot] com

  10. Mary Lou Pullen

    Good Morning Kat! I just want to thank you for all your great information that is making my first time working with Succulents so exciting with all your information. I so appreciate it.
    Lou Pullen

    1. Kat McCarthy

      Hi Mary Lou,
      That’s just awesome! Thank you for letting me be a part of your succulent journey! 🙂

  11. Soeisna Leong

    Thank You for all excellent explanation on all plants . I learn a lot .
    I am glad subscribe Your Email and the Nursery has a lot of good choices !

    1. Kat McCarthy

      Thanks SO much, Soeisna!
      So glad you’re finding the information valuable.

  12. Linda Huckauff

    Loving my journey with succulents. Your posts are so informative. I live in South Australia – driest state in Australia – true we get rain but almost zero humidity.
    Shame we cannot get plants from US suppliers.

    1. Kat McCarthy

      Hi Linda,
      Thanks so much for bringing me along on your adventures in succulents! 🙂
      I do wish agricultural imports didn’t have to be so strictly regulated, but the problems that can occur are SO damaging, it really is for the best. Maybe there are some really interesting sellers in Australia you haven’t found yet? You’re welcome to join my Facebook group for succulent lovers! Ask our other members from Australia where they get their beauties!
      I hope to see you there!

  13. Hobbs

    Does crassula ovata ogre ears succulent have epicuticular wax? The stuff on mine isn’t even, but it doesn’t look like mildew or mold. Also, do seashells crushed into powder work as a good chitinase source for succulents?

    1. Kat McCarthy

      Hi Hobbs,
      No, Crassula ovata Ogre’s Ears doesn’t have epicuticular wax. Strange! What you describe sounds like mildew… If you want to send me a photo, I’ll be happy to take a look for you!
      I would expect that the chitinase in seashells would not be accessible for the succulents, but I don’t know for sure…

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