Plant Problems? The Sill's Resident Botanist Will Give You a Diagnosis (and a Solution!) via Email or Text

Composite, Mental Floss. Illustrations, iStock.
Composite, Mental Floss. Illustrations, iStock. / Composite, Mental Floss. Illustrations, iStock.

Taking care of succulents is easy, or so they say. But that has never been true for me and my opposite-of-green-thumb. Aside from my beloved marimos, all the plants in my care shrivel and die. Their leafy language is one I just can't seem to understand. 

So when my future mother-in-law sent me a succulent arrangement last summer, I was nervous that it, too, would meet a terrible fate (and frankly, it feels like a bad omen to kill a plant given to you by your fiancé's mom). But I placed it in a bright window next to my desk at work, watered it according to the instructions, and watched with delight as the plants thrived. The Gymnocalycium cactus even flowered three times! It seemed that my plant killing streak was over.

My arrangement in its glory days.
My arrangement in its glory days. / Erin McCarthy

And then, one of the cactuses began sporting little white spots.

At first, I assumed the spots were just a cactus thing. But they quickly covered the plant in fuzz and began to spread across the arrangement. Panicked, I Googled "white fuzzy spots on plants," which returned millions of results, diagnosing everything from mold to bugs. With no clear answers available, I cut as much of the fuzzy cactus as I could out of the arrangement (it's potted in hard soil, making removal difficult) and bought a spray bottle to douse the plants with soapy water. That seemed to slow the spots down—but they weren't disappearing.

It eventually became obvious that I needed expert help, so I emailed The Sill.


Courtesy of The Sill

This New York City-based plant paradise—whose catchphrase is "plants make people happy"—was founded in 2012. Its goal, founder Eliza Blank told Coveteur, is "demystifying plant care for novices … it's really part of the mission to help those who are plant-curious but don't really know what they're doing."

To that end, The Sill offers weekly workshops, a page of common questions covering everything from the basics ("How do I choose a plant?") to "stranger things" ("What's that smell?"), and a section devoted to plant care called "Your Journey to Plant Parenthood." And if after all of that you still can't find a solution to your plant problems, you can fill out the questionnaire, send an email, or text with photos. Within a couple of days, you'll hear back from Christopher Satch, The Sill's resident botanist.

Satch, who joined The Sill in 2015, has botany in his blood—his grandparents are avid gardeners, and his father owns an orchard in New Jersey. "I've always loved plants," he tells Mental Floss via email. "They're fascinating with their secret world that's in plain sight—the way they grow, the slow movements that they make, their interactions with their environment." He likes how clean they are—"plants don’t poop everywhere or smell bad"—and finds it amazing that "they've mastered chemistry in a way that seems like witchcraft or alchemy. They create something from what is essentially nothing: Air, water, and minerals are all they need to make fruit, sugars, colors, flowers, everything. Their shapes, patterns, colors, and productivity have not only inspired civilizations but built them … We would be nothing without plants."


Courtesy of The Sill

Satch's passion for plants is obvious, and he brings that enthusiasm to every plant workshop he runs at The Sill (during which he covers not just care but also history and relevance to daily life, because "understanding how interconnected our world is, I think, is also important"), and to every desperate plant-owner email he responds to. He gets hundreds of emails a month, and sometimes five texts a day.

Though Satch gets a wide variety of issues sent to him, they mostly boil down to two things: aesthetics—people notice that their plant has dropped a leaf and they're panicking—and people trying to make plants work in low-light environments. "Repeat it as your mantra: Light is food for plants. The more light, generally the better they do," he says. "Anything more than a few feet from a window, no matter how bright it looks, is considered to be low light. An old horticultural adage [says], 'The darkest shade outdoors is still many times brighter than a sunny window indoors,' and that's very true."

Both issues can be seen in one particular case: Satch was once contacted by a woman in Italy who had inherited her grandmother's 70-year-old Ficus elastica, and it wasn't looking so hot. Ficus elastica and all other Ficus plants are finicky, Satch says: "They will drop their leaves in response to not enough light. She was told that rubber trees are low light plants—and they can be, they'll just drop most of their leaves to compensate for the lack of light, and therefore food. She, however, wanted a fuller plant. For fuller plants, more light is needed to maintain bushiness."

The issue, Satch thinks, is that people "treat plants like objects, or expect them to react like animals would," he says. "Like in diplomacy, to reach someone, you have to speak their language. It's definitely a matter of understanding that plants will react slowly, and that they will react to their environment as a whole … They're living creatures and some thought needs to be taken as to what they need and are sensitive to."


The arrangment after a few months of winter—and a mealybug infestation.
The arrangment after a few months of winter—and a mealybug infestation. / Erin McCarthy

I send Satch several pictures of my sad succulents, outlining when I'd gotten the plant and how I'd unsuccessfully tried to treat it so far.

Satch gets back to me the same day with a diagnosis: Those fuzzy white spots are most likely mealybugs. "Mealybugs are dispersed in most environments," he says. "There may be residual eggs on a new plant you bring home, or in the soil, dormant. Most commonly, though, they come through windows that are open, or from plants brought inside from the outside." The best way to get rid of them, he says, is with a solution of hort oil or insecticidal soap; he recommends the exact kind of spray to get and instructs me to trim all the dead matter off the plants before spraying them with the insecticidal soap.

The arrangement has some other issues, too: Satch says some of the succulents are looking dry and one in particular looks like it needs more light.

Satch's advice thankfully also came with some assurances. "You're not doing as badly as you think!" he says. "Aloe ciliaris looks fine … The golden barrel cactus looks fabulous. The Kalanchoe also looks super fab! Keep up the good work with that!"

I do as Satch suggested: purchasing the insecticidal soap, trimming the plants of dead matter, giving them a good spray. I also rotate the arrangement so that the Graptopetalum—which was pale, Satch says, because it needed more light—toward the window. Within days, it was a darker shade of green. A week later, I spray my succulents with the insecticidal soap again. The white spots seem to be disappearing. So far, so good.

Erin McCarthy

When brown spots pop up on my Graptopetalum (Google diagnosis: edema, sunburn), I email Satch again. "I have good news and bad news," he responds. "The good news is, is that there are dead mealybugs there—yay!" The bad news: Those brown and white spots are scale bugs. "Scale are easy to get rid of, but there's only one way—you have to scrape off each one individually, then follow up with an alcohol wipe to kill any eggs," he says. Infestations like the ones I'm experiencing are all too common, and in my case, they probably came with the plant. "To the untrained eye, they kind of blend in with the plants, which is why they've been evolutionarily successful, too—so it's understandable how they're missed," he says. "At both the university and the botanic gardens, we always say that the best way to avoid infestations is to select good stock from reputable sources."


Courtesy of The Sill

As I'm finding out firsthand, plant care has its challenges—but it's awesome to have an expert you can email directly who will help you troubleshoot and give advice so that you don't get discouraged. "You can make most situations work, you just have to be willing to put in the effort to make sure that the plant gets enough light," Satch says.

And if you're still nervous, keep this in mind: Even Satch, a person with a master's degree in plant biology and pathology, has killed plants. "One of the most memorable plants that I've killed was an unknown orchid species I inherited," he says. "It dropped all of its leaves, and no matter what I did, it didn't improve." He put it in the sun; when that didn't work, he put it in the shade. He tried two weeks of watering more, then two weeks of watering less. The stems of the plant were green, but it wouldn't stop dropping leaves. So, he says, "in a last ditch effort, I placed the plant outside."

It was a fatal mistake. "I unwittingly cooked my plant to death in the scorching sun," he says. "I later learned that it was a Dendrobium orchid that goes deciduous, and that orchids react to things very slowly." But even killing plants, he says, can be a learning experience.

So now, to be the best plant mom I can be, I'm looking back at my plant-care experiences and taking lessons from them. And one day, a couple of weeks after tackling my succulent problems, I went to The Sill's Hester Street store and bought a pet-friendly, low-light-happy bird's nest fern—the perfect plant for my apartment. It's comforting to know that if anything should happen, Satch is just an email away.

To contact The Sill, send an email to or text 646-831-2216.